Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IX: The Ninth Year (2016–2017)

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IX: The Ninth Year (2016–2017)

Taichi Kato    \ref{affil:Kyoto}*\ref{affil:Kyoto}*affiliationmark: Keisuke Isogai    \ref{affil:Kyoto}\ref{affil:Kyoto}affiliation: Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan Franz-Josef Hambsch    \ref{affil:GEOS}\ref{affil:GEOS}affiliation: Groupe Européen d’Observations Stellaires (GEOS), 23 Parc de Levesville, 28300 Bailleau l’Evêque, France \ref{affil:BAV}\ref{affil:BAV}affiliation: Bundesdeutsche Arbeitsgemeinschaft für Veränderliche Sterne (BAV), Munsterdamm 90, 12169 Berlin, Germany \ref{affil:Hambsch}\ref{affil:Hambsch}affiliation: Vereniging Voor Sterrenkunde (VVS), Oude Bleken 12, 2400 Mol, Belgium Tonny Vanmunster    \ref{affil:Vanmunster}\ref{affil:Vanmunster}affiliation: Center for Backyard Astrophysics Belgium, Walhostraat 1A, B-3401 Landen, Belgium Hiroshi Itoh    \ref{affil:Ioh}\ref{affil:Ioh}affiliation: Variable Star Observers League in Japan (VSOLJ), 1001-105 Nishiterakata, Hachioji, Tokyo 192-0153, Japan Berto Monard    \ref{affil:Monard}\ref{affil:Monard}affiliation: Bronberg Observatory, Center for Backyard Astrophysics Pretoria, PO Box 11426, Tiegerpoort 0056, South Africa \ref{affil:Monard2}\ref{affil:Monard2}affiliation: Kleinkaroo Observatory, Center for Backyard Astrophysics Kleinkaroo, Sint Helena 1B, PO Box 281, Calitzdorp 6660, South Africa Tamás Tordai    \ref{affil:Polaris}\ref{affil:Polaris}affiliation: Polaris Observatory, Hungarian Astronomical Association, Laborc utca 2/c, 1037 Budapest, Hungary Mariko Kimura    \ref{affil:Kyoto}\ref{affil:Kyoto}affiliation: Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan Yasuyuki Wakamatsu    \ref{affil:Kyoto}\ref{affil:Kyoto}affiliation: Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan Seiichiro Kiyota    \ref{affil:Kis}\ref{affil:Kis}affiliation: VSOLJ, 7-1 Kitahatsutomi, Kamagaya, Chiba 273-0126, Japan Ian Miller    \ref{affil:Miller}\ref{affil:Miller}affiliation: Furzehill House, Ilston, Swansea, SA2 7LE, UK Peter Starr    \ref{affil:Starr}\ref{affil:Starr}affiliation: Warrumbungle Observatory, Tenby, 841 Timor Rd, Coonabarabran NSW 2357, Australia Kiyoshi Kasai    \ref{affil:Kai}\ref{affil:Kai}affiliation: Baselstrasse 133D, CH-4132 Muttenz, Switzerland Sergey Yu. Shugarov    \ref{affil:Sternberg}\ref{affil:Sternberg}affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Ave., 13, Moscow 119992, Russia \ref{affil:Slovak}\ref{affil:Slovak}affiliation: Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranska Lomnica, Slovakia Drahomir Chochol    \ref{affil:Slovak}\ref{affil:Slovak}affiliation: Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranska Lomnica, Slovakia Natalia Katysheva    \ref{affil:Sternberg}\ref{affil:Sternberg}affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Ave., 13, Moscow 119992, Russia Anna M. Zaostrojnykh    \ref{affil:Kazan}\ref{affil:Kazan}affiliation: Institute of Physics, Kazan Federal University, Ulitsa Kremlevskaya 16a, Kazan 420008, Russia Matej Sekeráš    \ref{affil:Slovak}\ref{affil:Slovak}affiliation: Astronomical Institute of the Slovak Academy of Sciences, 05960 Tatranska Lomnica, Slovakia Yuliana G. Kuznyetsova    \ref{affil:MainUkraine}\ref{affil:MainUkraine}affiliation: Main Astronomical Observatory of National Academy of Sciences of Ukraine, 27 Akademika Zabolotnoho St., Kyiv 03143, Ukraine Eugenia S. Kalinicheva    \ref{affil:Moscow}\ref{affil:Moscow}affiliation: Faculty of Physics, Lomonosov Moscow State University, Leninskie gory, Moscow 119991, Russia Polina Golysheva    \ref{affil:Sternberg}\ref{affil:Sternberg}affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Ave., 13, Moscow 119992, Russia Viktoriia Krushevska    \ref{affil:MainUkraine}\ref{affil:MainUkraine}affiliation: Main Astronomical Observatory of National Academy of Sciences of Ukraine, 27 Akademika Zabolotnoho St., Kyiv 03143, Ukraine Yutaka Maeda    \ref{affil:Mdy}\ref{affil:Mdy}affiliation: Kaminishiyamamachi 12-14, Nagasaki, Nagasaki 850-0006, Japan Pavol A. Dubovsky    \ref{affil:Dubovsky}\ref{affil:Dubovsky}affiliation: Vihorlat Observatory, Mierova 4, 06601 Humenne, Slovakia Igor Kudzej    \ref{affil:Dubovsky}\ref{affil:Dubovsky}affiliation: Vihorlat Observatory, Mierova 4, 06601 Humenne, Slovakia Elena P. Pavlenko    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea \ref{affil:CrimeanFU}\ref{affil:CrimeanFU}affiliation: V. I. Vernadsky Crimean Federal University, 4 Vernadskogo Prospekt, Simferopol, 295007, Republic of Crimea Kirill A. Antonyuk    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Nikolaj V. Pit    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Aleksei A. Sosnovskij    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Oksana I. Antonyuk    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Aleksei V. Baklanov    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Roger D. Pickard    \ref{affil:BAAVSS}\ref{affil:BAAVSS}affiliation: The British Astronomical Association, Variable Star Section (BAA VSS), Burlington House, Piccadilly, London, W1J 0DU, UK \ref{affil:Pickard}\ref{affil:Pickard}affiliation: 3 The Birches, Shobdon, Leominster, Herefordshire, HR6 9NG, UK Naoto Kojiguchi    \ref{affil:OKU}\ref{affil:OKU}affiliation: Osaka Kyoiku University, 4-698-1 Asahigaoka, Osaka 582-8582, Japan Yuki Sugiura    \ref{affil:OKU}\ref{affil:OKU}affiliation: Osaka Kyoiku University, 4-698-1 Asahigaoka, Osaka 582-8582, Japan Shihei Tei    \ref{affil:OKU}\ref{affil:OKU}affiliation: Osaka Kyoiku University, 4-698-1 Asahigaoka, Osaka 582-8582, Japan Kenta Yamamura    \ref{affil:OKU}\ref{affil:OKU}affiliation: Osaka Kyoiku University, 4-698-1 Asahigaoka, Osaka 582-8582, Japan Katsura Matsumoto    \ref{affil:OKU}\ref{affil:OKU}affiliation: Osaka Kyoiku University, 4-698-1 Asahigaoka, Osaka 582-8582, Japan Javier Ruiz    \ref{affil:Ruiz1}\ref{affil:Ruiz1}affiliation: Observatorio de Cántabria, Ctra. de Rocamundo s/n, Valderredible, 39220 Cantabria, Spain \ref{affil:Ruiz2}\ref{affil:Ruiz2}affiliation: Instituto de Física de Cantabria (CSIC-UC), Avenida Los Castros s/n, E-39005 Santander, Cantabria, Spain \ref{affil:Ruiz3}\ref{affil:Ruiz3}affiliation: Agrupación Astronómica Cántabria, Apartado 573, 39080, Santander, Spain Geoff Stone    \ref{affil:AAVSO}\ref{affil:AAVSO}affiliation: American Association of Variable Star Observers, 49 Bay State Rd., Cambridge, MA 02138, USA Lewis M. Cook    \ref{affil:LewCook}\ref{affil:LewCook}affiliation: Center for Backyard Astrophysics Concord, 1730 Helix Ct. Concord, California 94518, USA Enrique de Miguel    \ref{affil:Miguel}\ref{affil:Miguel}affiliation: Departamento de Ciencias Integradas, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva, Spain \ref{affil:Miguel2}\ref{affil:Miguel2}affiliation: Center for Backyard Astrophysics, Observatorio del CIECEM, Parque Dunar, Matalascañas, 21760 Almonte, Huelva, Spain Hidehiko Akazawa    \ref{affil:OUS}\ref{affil:OUS}affiliation: Department of Biosphere-Geosphere System Science, Faculty of Informatics, Okayama University of Science, 1-1 Ridai-cho, Okayama, Okayama 700-0005, Japan William N. Goff    \ref{affil:Goff}\ref{affil:Goff}affiliation: 13508 Monitor Ln., Sutter Creek, California 95685, USA Etienne Morelle    \ref{affil:Morelle}\ref{affil:Morelle}affiliation: 9 rue Vasco de GAMA, 59553 Lauwin Planque, France Stella Kafka    \ref{affil:AAVSO}\ref{affil:AAVSO}affiliation: American Association of Variable Star Observers, 49 Bay State Rd., Cambridge, MA 02138, USA Colin Littlefield    \ref{affil:LCO}\ref{affil:LCO}affiliation: Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, Indiana 46556, USA Greg Bolt    \ref{affil:Bolt}\ref{affil:Bolt}affiliation: Camberwarra Drive, Craigie, Western Australia 6025, Australia Franky Dubois    \ref{affil:Dubois}\ref{affil:Dubois}affiliation: Public observatory Astrolab Iris, Verbrandemolenstraat 5, B 8901 Zillebeke, Belgium Stephen M. Brincat    \ref{affil:Brincat}\ref{affil:Brincat}affiliation: Flarestar Observatory, San Gwann SGN 3160, Malta Hiroyuki Maehara    \ref{affil:OAO}\ref{affil:OAO}affiliation: Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232, Japan Takeshi Sakanoi    \ref{affil:TohokuPlanetary}\ref{affil:TohokuPlanetary}affiliation: Planetary Plasma and Atmospheric Research Center, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan Masato Kagitani    \ref{affil:TohokuPlanetary}\ref{affil:TohokuPlanetary}affiliation: Planetary Plasma and Atmospheric Research Center, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan Akira Imada    \ref{affil:Hamburg}\ref{affil:Hamburg}affiliation: Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, D-21029 Hamburg, Germany \ref{affil:HidaKwasan}\ref{affil:HidaKwasan}affiliation: Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471, Japan Irina B. Voloshina    \ref{affil:Sternberg}\ref{affil:Sternberg}affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Ave., 13, Moscow 119992, Russia Maksim V. Andreev    \ref{affil:Terskol}\ref{affil:Terskol}affiliation: Terskol Branch of Institute of Astronomy, Russian Academy of Sciences, 361605, Peak Terskol, Kabardino-Balkaria Republic, Russia \ref{affil:ICUkraine}\ref{affil:ICUkraine}affiliation: International Center for Astronomical, Medical and Ecological Research of NASU, Ukraine 27 Akademika Zabolotnoho Str. 03680 Kyiv, Ukraine Richard Sabo    \ref{affil:Sabo}\ref{affil:Sabo}affiliation: 2336 Trailcrest Dr., Bozeman, Montana 59718, USA Michael Richmond    \ref{affil:RIT}\ref{affil:RIT}affiliation: Physics Department, Rochester Institute of Technology, Rochester, New York 14623, USA Tony Rodda    \ref{affil:Rodda}\ref{affil:Rodda}affiliation: 1, Rivermede, Ponteland, Newcastle upon Tyne, NE20 9XA, UK Peter Nelson    \ref{affil:Nelson}\ref{affil:Nelson}affiliation: 1105 Hazeldean Rd, Ellinbank 3820, Australia Sergey Nazarov    \ref{affil:CrAO}\ref{affil:CrAO}affiliation: Federal State Budget Scientific Institution “Crimean Astrophysical Observatory of RAS”, Nauchny, 298409, Republic of Crimea Nikolay Mishevskiy    \ref{affil:AAVSO}\ref{affil:AAVSO}affiliation: American Association of Variable Star Observers, 49 Bay State Rd., Cambridge, MA 02138, USA Gordon Myers    \ref{affil:Myers}\ref{affil:Myers}affiliation: Center for Backyard Astrophysics San Mateo, 5 inverness Way, Hillsborough, CA 94010, USA Denis Denisenko    \ref{affil:Sternberg}\ref{affil:Sternberg}affiliation: Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Ave., 13, Moscow 119992, Russia Krzysztof Z. Stanek    \ref{affil:Ohio}\ref{affil:Ohio}affiliation: Department of Astronomy, the Ohio State University, Columbia, OH 43210, USA Joseph V. Shields    \ref{affil:Ohio}\ref{affil:Ohio}affiliation: Department of Astronomy, the Ohio State University, Columbia, OH 43210, USA Christopher S. Kochanek    \ref{affil:Ohio}\ref{affil:Ohio}affiliation: Department of Astronomy, the Ohio State University, Columbia, OH 43210, USA Thomas W.-S. Holoien    \ref{affil:Ohio}\ref{affil:Ohio}affiliation: Department of Astronomy, the Ohio State University, Columbia, OH 43210, USA Benjamin Shappee    \ref{affil:Carnegie}\ref{affil:Carnegie}affiliation: Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101, USA José L. Prieto    \ref{affil:DiegoPortales}\ref{affil:DiegoPortales}affiliation: Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago, Chile \ref{affil:Princeton}\ref{affil:Princeton}affiliation: Department of Astrophysical Sciences, Princeton University, NJ 08544, USA Koh-ichi Itagaki    \ref{affil:Itagaki}\ref{affil:Itagaki}affiliation: Itagaki Astronomical Observatory, Teppo-cho, Yamagata 990-2492 Koichi Nishiyama    \ref{affil:MiyakiObs}\ref{affil:MiyakiObs}affiliation: Miyaki-Argenteus Observatory, Miyaki, Saga 840-1102, Japan Fujio Kabashima    \ref{affil:MiyakiObs}\ref{affil:MiyakiObs}affiliation: Miyaki-Argenteus Observatory, Miyaki, Saga 840-1102, Japan Rod Stubbings    \ref{affil:Stubbings}\ref{affil:Stubbings}affiliation: Tetoora Observatory, 2643 Warragul-Korumburra Road, Tetoora Road, Victoria 3821, Australia Patrick Schmeer    \ref{affil:Schmeer}\ref{affil:Schmeer}affiliation: Bischmisheim, Am Probstbaum 10, 66132 Saarbrücken, Germany Eddy Muyllaert    \ref{affil:VVSBelgium}\ref{affil:VVSBelgium}affiliation: Vereniging Voor Sterrenkunde (VVS), Moffelstraat 13 3370 Boutersem, Belgium Tsuneo Horie    \ref{affil:Heo}\ref{affil:Heo}affiliation: 759-10 Tokawa, Hadano-shi, Kanagawa 259-1306, Japan Jeremy Shears    \ref{affil:Shears}\ref{affil:Shears}affiliation: “Pemberton”, School Lane, Bunbury, Tarporley, Cheshire, CW6 9NR, UK \ref{affil:BAAVSS}\ref{affil:BAAVSS}affiliation: The British Astronomical Association, Variable Star Section (BAA VSS), Burlington House, Piccadilly, London, W1J 0DU, UK Gary Poyner    \ref{affil:Poyner}\ref{affil:Poyner}affiliation: BAA Variable Star Section, 67 Ellerton Road, Kingstanding, Birmingham B44 0QE, UK Masayuki Moriyama    \ref{affil:Myy}\ref{affil:Myy}affiliation: 290-383, Ogata-cho, Sasebo, Nagasaki 858-0926, Japan tkato@kusastro.kyoto-u.ac.jp
Abstract

Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 127 SU UMa-type dwarf novae observed mainly during the 2016–2017 season and characterized these objects. We provide updated statistics of relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. We obtained the period minimum of 0.05290(2) d and confirmed the presence of the period gap above the orbital period 0.09 d. We note that four objects (NY Her, 1RXS J161659.5620014, CRTS J033349.8282244 and SDSS J153015.04094946.3) have supercycles shorter than 100 d but show infrequent normal outbursts. We consider that these objects are similar to V503 Cyg, whose normal outbursts are likely suppressed by a disk tilt. These four objects are excellent candidates to search for negative superhumps. DDE 48 appears to be a member of ER UMa-type dwarf novae. We identified a new eclipsing SU UMa-type object MASTER OT J220559.40341434.9. We observed 21 WZ Sge-type dwarf novae during this interval and reported 18 out of them in this paper. Among them, ASASSN-16js is a good candidate for a period bouncer. ASASSN-16ia showed a precursor outburst for the first time in a WZ Sge-type superoutburst. ASASSN-16kg, CRTS J000130.5050624 and SDSS J113551.09532246.2 are located in the period gap. We have newly obtained 15 orbital periods, including periods from early superhumps.

\SetRunningHead

T. Kato et al.Period Variations in SU UMa-Type Dwarf Novae IX

\Received

201X/XX/XX\Accepted201X/XX/XX

\KeyWords

accretion, accretion disks — stars: novae, cataclysmic variables — stars: dwarf novae

1 Introduction

This is a continuation of series of papers Kato et al. (2009), Kato et al. (2010), Kato et al. (2012a), Kato et al. (2013), Kato et al. (2014b), Kato et al. (2014a), Kato et al. (2015a) and Kato et al. (2016a) reporting new observations of superhumps in SU UMa-type dwarf novae. SU UMa-type dwarf novae are a class of cataclysmic variables (CVs) which are close binary systems transferring matter from a low-mass dwarf secondary to a white dwarf, forming an accretion disk [see e.g. Warner (1995) for CVs in general].

In SU UMa-type dwarf novae, there are two types of outbursts (normal outbursts and superoutbursts). Outbursts and superoutbursts in SU UMa-type dwarf novae are considered to be a result of the combination of thermal and tidal instabilities [thermal-tidal instability (TTI) model by Osaki (1989); Osaki (1996)].

During superoutbursts, semi-periodic variations called superhumps are observed whose period (superhump period, ) is a few percent longer than the orbital period (). Superhumps are considered to originate from a precessing eccentric (or flexing) disk in the gravity field of the rotating binary, and the eccentricity in the disk is believed to be a consequence of the 3:1 resonance in the accretion disk [see e.g. Whitehurst (1988); Hirose and Osaki (1990); Lubow (1991); Wood et al. (2011)].

It has become evident since Kato et al. (2009) that the superhump periods systematically vary in a way common to many objects. Kato et al. (2009) introduced superhump stages (stages A, B and C): initial growing stage with a long period (stage A) and fully developed stage with a systematically varying period (stage B) and later stage C with a shorter, almost constant period (see figure 1).

It has recently been proposed by Osaki and Kato (2013b) that stage A superhumps reflect the dynamical precession rate at the 3:1 resonance radius and that the rapid decrease of the period (stage B) reflects the pressure effect which has an effect of retrograde precession (Lubow (1992); Hirose and Osaki (1993); Murray (1998); Montgomery (2001); Pearson (2006)). As proposed by Kato and Osaki (2013) stage A superhumps can be then used to “dynamically” determine the mass ratio (), which had been difficult to measure except for eclipsing systems and systems with bright secondaries to detect radial-velocity variations. It has been confirmed that this stage A method gives values as precise as in eclipsing systems. There have been more than 50 objects whose values are determined by this method and it has been proven to be an especially valuable tool in depicting the terminal stage of CV evolution (cf. Kato et al. (2015a); Kato (2015)).

In this paper, we present new observations of SU UMa-type dwarf novae mainly obtained in 2016–2017. We present basic observational materials and discussions in relation to individual objects. Starting from Kato et al. (2014a), we have been intending these series of papers to be also a source of compiled information, including historical, of individual dwarf novae.

\FigureFile

(80mm,110mm)stagerev.eps

Figure 1: Representative diagram showing three stages (A–C) of variation. The data were taken from the 2000 superoutburst of SW UMa. (Upper:) diagram. Three distinct stages (A – evolutionary stage with a longer superhump period, B – middle stage, and C – stage after transition to a shorter period) and the location of the period break between stages B and C are shown. (Middle): Amplitude of superhumps. During stage A, the amplitude of the superhumps grew. (Lower:) Light curve. (Reproduction of figure 1 in Kato and Osaki (2013))

The material and methods of analysis are given in section 2, observations and analysis of individual objects are given in section 3, including discussions particular to the objects. General discussions are given in section 4 and the summary is given in section 5. Some tables and figures are available online only.

2 Observation and Analysis

2.1 Data Source

The data were obtained under campaigns led by the VSNET Collaboration (Kato et al., 2004). We also used the public data from the AAVSO International Database111 http://www.aavso.org/data-download. . Outburst detections of many new and known objects relied on the ASAS-SN CV patrol (Davis et al., 2015)222 http://cv.asassn.astronomy.ohio-state.edu/. , the MASTER network (Gorbovskoy et al., 2013), and Catalina Real-time Transient Survey (CRTS; Drake et al. (2009))333 http://nesssi.cacr.caltech.edu/catalina/. For the information of the individual Catalina CVs, see http://nesssi.cacr.caltech.edu/catalina/AllCV.html. in addition to outburst detections reported to VSNET, AAVSO444 https://www.aavso.org/. , BAAVSS alert555 https://groups.yahoo.com/neo/groups/baavss-alert/. and cvnet-outburst.666 https://groups.yahoo.com/neo/groups/cvnet-outburst/.

For objects detected in CRTS, we preferably used the names provided in Drake et al. (2014) and Coppejans et al. (2016). If these names are not yet available, we used the International Astronomical Union (IAU)-format names provided by the CRTS team in the public data release777 http://nesssi.cacr.caltech.edu/DataRelease/. Since Kato et al. (2009), we have used coordinate-based optical transient (OT) designations for some objects, such as apparent dwarf nova candidates reported in the Transient Objects Confirmation Page of the Central Bureau for Astronomical Telegrams888 http://www.cbat.eps.harvard.edu/unconf/tocp.html. and CRTS objects without registered designations in Drake et al. (2014) or in the CRTS public data release and listed the original identifiers in table 1.

We provided coordinates from astrometric catalogs for ASAS-SN (Shappee et al., 2014) CVs and two objects without precise coordinate-based names other than listed in the General Catalog of Variable Stars (Kholopov et al., 1985) in table 2. We mainly used Gaia DR1 (Gaia Collaboration, 2016), Sloan Digital Sky Survey (SDSS, Ahn et al. (2012)), the Initial Gaia Source List (IGSL, Smart (2013)) and Guide Star Catalog 2.3.2 (GSC 2.3.2, Lasker et al. (2007)). Some objects were detected as transients by Gaia999 http://gsaweb.ast.cam.ac.uk/alerts/alertsindex and Gaia identifications supplied by the AAVSO VSX. and CRTS and we used their coordinates. The coordinates used in this paper are J2000.0. We also supplied SDSS , Gaia and GALEX NUV magnitudes when counterparts are present.

2.2 Observations and Basic Reduction

The majority of the data were acquired by time-resolved CCD photometry by using 20–60cm telescopes located world-wide. The list of outbursts and observers is summarized in table 1. The data analysis was performed in the same way described in Kato et al. (2009) and Kato et al. (2014a) and we mainly used R software101010 The R Foundation for Statistical Computing:
http://cran.r-project.org/.
for data analysis.

In de-trending the data, we mainly used locally-weighted polynomial regression (LOWESS: Cleveland (1979)) and sometimes lower (1–3rd order) polynomial fitting when the observation baseline was short. The times of superhumps maxima were determined by the template fitting method as described in Kato et al. (2009). The times of all observations are expressed in barycentric Julian days (BJD).

In figures, the points are accompanied by 1 error bars whenever available, which are omitted when the error is smaller than the plot mark or the errors were not available (as in some raw light curves of superhumps).

2.3 Abbreviations and Terminology

The abbreviations used in this paper are the same as in Kato et al. (2014a): we used for the fractional superhump excess. We have used since Osaki and Kato (2013a) the alternative fractional superhump excess in the frequency unit because this fractional superhump excess is a direct measure of the precession rate. We therefore used in discussing the precession rate.

The , and other parameters are listed in table 3 in same format as in Kato et al. (2009). The definitions of parameters and are the same as in Kato et al. (2009): and represent periods in stage B and C, respectively ( is averaged during the entire course of the observed segment of stage B), and and represent intervals (in cycle numbers) to determine and , respectively.111111 The intervals ( and ) for the stages B and C given in the table sometimes overlap because there is sometimes observational ambiguity (usually due to the lack of observations and errors in determining the times of maxima) in determining the stages. Some superoutbursts are not listed in table 3 due to the lack of observations (e.g. single-night observations with less than two superhump maxima or poor observations for the object with already well measured ).

We used the same terminology of superhumps summarized in Kato et al. (2012a). We especially call attention to the term “late superhumps”. We only used the concept of “traditional” late superhumps when there is an 0.5 phase shift [Vogt (1983); see also table 1 in Kato et al. (2012a) for various types of superhumps], since we suspect that many of the past claims of detections of “late superhumps” were likely stage C superhumps before it became evident that there are complex structures in the diagrams of superhumps (see discussion in Kato et al. (2009)).

2.4 Period Analysis

We used phase dispersion minimization (PDM; Stellingwerf (1978)) for period analysis and 1 errors for the PDM analysis was estimated by the methods of Fernie (1989) and Kato et al. (2010). We have used a variety of bootstrapping in estimating the robustness of the result of the PDM analysis since Kato et al. (2012a). We analyzed 100 samples which randomly contain 50% of observations, and performed PDM analysis for these samples. The bootstrap result is shown as a form of 90% confidence intervals in the resultant PDM statistics. If this paper provides the first solid presentation of a new SU UMa-type classification, we provide the result of PDM period analysis and averaged superhump profile.

2.5 Diagrams

Comparisons of diagrams between different superoutbursts are also presented whenever available. This figure not only provides information about the difference of diagrams between different superoutbursts but also helps identifying superhump stages especially when observations were insufficient or the start of the outburst was missed. In drawing combined diagrams, we usually used 0 for the start of the superoutburst, which usually refers to the first positive detection of the outburst. This epoch usually has an accuracy of 1 d for well-observed objects, and if the outburst was not sufficiently observed, we mentioned in the figure caption how to estimate in such an outburst. In some cases, this 0 is defined as the appearance of superhumps. This treatment is necessary since some objects have a long waiting time before appearance of superhumps. We also note that there is sometimes an ambiguity in selecting the true period among aliases. In some cases, this can be resolved by the help of the analysis. The procedure and example are shown in subsection 2.2 in Kato et al. (2015a).

Subsection Object Year Observers or references ID
3.1 V1047 Aql 2016 Trt
3.2 BB Ari 2016 Kis, AAVSO, SRI, RPc, Ioh,
Shu, RAE
3.3 V391 Cam 2017 Trt, DPV
3.4 OY Car 2016 SPE, HaC, MGW
HT Cas 2016 Y. Wakamatsu et al. in preparation
3.5 GS Cet 2016 Kis, OKU, HaC, Shu, CRI,
KU, Ioh, Trt
3.6 GZ Cet 2016 OKU
3.7 AK Cnc 2016 Aka
3.8 GZ Cnc 2017 KU, Mdy, HaC
3.9 GP CVn 2016 RPc, Kai, Trt, IMi, Kis,
CRI, deM, AAVSO
3.10 V337 Cyg 2016 Kai
3.11 V1113 Cyg 2016 OKU, Ioh, Kis
3.12 IX Dra 2016 Kis, SGE, COO

Key to observers: Aka (H. Akazawa, OUS), BSM(S. Brincat), COO (L. Cook), CRI (Crimean Astrophys. Obs.), DDe (D. Denisenko), deM (E. de Miguel), DPV (P. Dubovsky), Dub (F. Dubois team), GBo (G. Bolt), GFB(W. Goff), HaC (F.-J. Hambsch, remote obs. in Chile), IMi(I. Miller), Ioh (H. Itoh), KU (Kyoto U., campus obs.), Kai (K. Kasai), Kis (S. Kiyota), LCO (C. Littlefield), MEV(E. Morelle), NGW (G. Myers), MLF (B. Monard), MNI (N. Mishevskiy), Mdy (Y. Maeda), Mhh (H. Maehara), NKa (N. Katysheva and S. Shugarov), Naz (S. Nazarov), Nel (P. Nelson), OKU (Osaya Kyoiku U.), RAE (T. Rodda), RIT (M. Richmond), RPc(R. Pickard), Rui (J. Ruiz), SGE(G. Stone), SPE(P. Starr), SRI(R. Sabo), Shu (S. Shugarov team), T60 (Haleakala Obs. T60 telescope), Trt (T. Tordai), Van (T. Vanmunster), Vol (I. Voloshina), AAVSO (AAVSO database)

Original identifications, discoverers or data source.
Inclusive of observations from the AAVSO database.
Table 1: List of Superoutbursts.
Subsection Object Year Observers or references ID
3.13 IR Gem 2016 Kai, Aka, CRI, BSM, AAVSO,
Trt
2017 Kai, Trt
3.14 NY Her 2016 GFB, Ioh, DPV, Trt, COO,
IMi, SGE
3.15 MN Lac 2016 Van
3.16 V699 Oph 2016 Kis, Ioh
3.17 V344 Pav 2016 HaC
3.18 V368 Peg 2016 Trt
3.19 V893 Sco 2016 GBo, HaC, Kis, Aka
3.20 V493 Ser 2016 Shu
3.21 AW Sge 2016 DPV
3.22 V1389 Tau 2016 HaC, KU, Ioh
3.23 SU UMa 2017 Trt
3.24 HV Vir 2016 HaC, DPV, AAVSO, deM, Mdy,
KU, RPc, GBo, Aka, IMi,
BSM, Kis
3.25 NSV 2026 2016b Trt, Dub
3.26 NSV 14681 2016 Van
3.27 1RXS J161659 2016 deM, MEV, IMi, Van, Trt 1RXS J161659.5620014
2016b MEV, DPV, IMi
3.28 ASASSN-13ak 2016 Trt, Kis
3.29 ASASSN-13al 2016 Van
3.30 ASASSN-13bc 2015 LCO, Rui, Trt
2016 SGE, Shu, NKa, Ioh, Rui
3.31 ASASSN-13bj 2016 Kai, OKU, Trt, SGE, DPV,
IMi, KU
3.32 ASASSN-13bo 2016 IMi, Shu
3.33 ASASSN-13cs 2016 SGE, KU, COO
3.34 ASASSN-13cz 2016 Kai, Trt, Rui, DPV
3.35 ASASSN-14gg 2016 Van, GFB
Table 1: List of Superoutbursts (continued).
Subsection Object Year Observers or references ID
3.36 ASASSN-15cr 2017 DPV, Ioh, Shu, CRI
3.37 ASASSN-16da 2016 deM, Van, GFB, SGE, Kai
3.38 ASASSN-16dk 2016 HaC
3.39 ASASSN-16ds 2016 MLF, HaC, SPE
ASASSN-16dt 2016 Kimura et al. (2017)
3.40 ASASSN-16dz 2016 Van
ASASSN-16eg 2016 Wakamatsu et al. (2017)
3.41 ASASSN-16ez 2016 DPV, Ioh, Kis, MEV, IMi,
Van, KU
3.42 ASASSN-16fr 2016 KU, Ioh, HaC
3.43 ASASSN-16fu 2016 HaC, MLF
ASASSN-16fy 2016 K. Isogai et al. in preparation
3.44 ASASSN-16gh 2016 MLF
3.45 ASASSN-16gj 2016 MLF, HaC
3.46 ASASSN-16gl 2016 MLF, HaC, DDe
ASASSN-16hg 2016 Kimura et al. (2017)
3.47 ASASSN-16hi 2016 HaC
3.48 ASASSN-16hj 2016 HaC, KU
3.49 ASASSN-16ia 2016 GFB, Ioh, Ter, Van, SGE,
CRI, COO, Trt
3.50 ASASSN-16ib 2016 MLF, HaC
3.51 ASASSN-16ik 2016 MLF, HaC
3.52 ASASSN-16is 2016 Shu, IMi, Van, Ioh, Rui
3.53 ASASSN-16iu 2016 HaC, MLF
3.54 ASASSN-16iw 2016 HaC, SPE, NKa, Kis, Van,
Ioh
3.55 ASASSN-16jb 2016 MLF, HaC, SPE
3.56 ASASSN-16jd 2016 HaC, Ioh
3.57 ASASSN-16jk 2016 CRI, Van
3.58 ASASSN-16js 2016 HaC, MLF, SPE
3.59 ASASSN-16jz 2016 Van
Table 1: List of Superoutbursts (continued).
Subsection Object Year Observers or references ID
3.60 ASASSN-16kg 2016 MLF, HaC
3.61 ASASSN-16kx 2016 HaC, MLF
3.62 ASASSN-16le 2016 KU, Ioh
3.63 ASASSN-16lj 2016 Van
3.64 ASASSN-16lo 2016 KU, IMi, OKU, Ioh
3.65 ASASSN-16mo 2016 OKU, KU, Trt, Dub, Van
3.66 ASASSN-16my 2016 HaC, Ioh
3.67 ASASSN-16ni 2016 KU, Ioh, Trt
3.68 ASASSN-16nq 2016 Kis, Ioh, RPc, Van, Trt
3.69 ASASSN-16nr 2016 MLF, HaC
3.70 ASASSN-16nw 2016 Kai
3.71 ASASSN-16ob 2016 MLF, HaC, SPE
3.72 ASASSN-16oi 2016 MLF, HaC, SPE
3.73 ASASSN-16os 2016 MLF, HaC, SPE
3.74 ASASSN-16ow 2016 Ioh, Van, NKa, Mdy, MEV,
Kis, Kai
3.75 ASASSN-17aa 2017 MLF, SPE, HaC
3.76 ASASSN-17ab 2017 HaC
3.77 ASASSN-17az 2017 MLF
3.78 ASASSN-17bl 2017 HaC, SPE
3.79 ASASSN-17bm 2017 MLF, HaC
3.80 ASASSN-17bv 2017 MLF, SPE, HaC
3.81 ASASSN-17ce 2017 SPE. MLF, HaC
3.82 ASASSN-17ck 2017 HaC
3.83 ASASSN-17cn 2017 MLF, SPE, HaC, Ioh
3.84 ASASSN-17cx 2017 Mdy
3.85 ASASSN-17dg 2017 HaC, MLF, SPE
3.86 ASASSN-17dq 2017 HaC, MLF
3.87 CRTS J000130 2016 Van, Shu CRTS J000130.5050624
3.88 CRTS J015321 2016 Kai CRTS J015321.5340857
3.90 CRTS J033349 2016 MLF, HaC, KU CRTS J033349.8282244
Table 1: List of Superoutbursts (continued).
Subsection Object Year Observers or references ID
3.89 CRTS J023638 2016 CRI, Trt, Shu, Rui CRTS J023638.0111157
3.91 CRTS J044637 2017 Ioh, KU CRTS J044636.9083033
3.92 CRTS J082603 2017 Van CRTS J082603.7113821
3.93 CRTS J085113 2008 Mhh CRTS J085113.4344449
2016 KU, Trt
3.94 CRTS J085603 2016 Van, Ioh CRTS J085603.8322109
3.95 CRTS J164950 2015 RIT, Van CRTS J164950.4035835
2016 CRI, Rui
3.96 CSS J062450 2017 Trt, Van CSS131223:062450503111
3.97 DDE 26 2016 Ioh, IMi, Shu, RPc
3.98 DDE 48 2016 MNI, IMi
3.99 MASTER J021315 2016 Van MASTER OT J021315.37533822.7
3.100 MASTER J030205 2016 OKU, deM, Van, COO, Ioh, MASTER OT J030205.67254834.3
Mdy, T60, NKa, RPc, Trt,
Naz
3.101 MASTER J042609 2016 Kis, Ioh, Kai, Shu, Trt MASTER OT J042609.34354144.8
3.102 MASTER J043220 2017 Van MASTER OT J043220.15784913.8
3.103 MASTER J043915 2016 Ioh, CRI MASTER OT J043915.60424232.3
3.104 MASTER J054746 2016 Van MASTER OT J054746.81762018.9
3.105 MASTER J055348 2017 Van, Mdy MASTER OT J055348.98482209.0
3.106 MASTER J055845 2016 Shu MASTER OT J055845.55391533.4
3.107 MASTER J064725 2016 Ioh, RPc, CRI MASTER OT J064725.70491543.9
3.108 MASTER J065330 2017 Van, Ioh MASTER OT J065330.46251150.9
3.109 MASTER J075450 2017 Van MASTER OT J075450.18091020.2
3.110 MASTER J150518 2017 HaC MASTER OT J150518.03143933.6
3.111 MASTER J151126 2016 HaC, MLF MASTER OT J151126.74400751.9
3.112 MASTER J162323 2015 Van MASTER OT J162323.48782603.3
2016 COO, Trt, IMi
3.113 MASTER J165153 2017 Van MASTER OT J165153.86702525.7
3.114 MASTER J174816 2016 Van, Mdy MASTER OT J174816.22501723.3
MASTER J191841 2016 K. Isogai et al. in preparation MASTER OT J191841.98444914.5
Table 1: List of Superoutbursts (continued).
Subsection Object Year Observers or references ID
3.115 MASTER J211322 2016 Van MASTER OT J211322.92260647.4
3.116 MASTER J220559 2016 MLF, HaC MASTER OT J220559.40341434.9
OT J002656 2016 Kato et al. (2017) CSS101212:002657284933
3.117 SBS 1108 2016 Ioh, COO, Vol, Kai, KU SBS 1108574
3.118 SDSS J032015 2016 Van, IMi SDSS J032015.29441059.3
3.119 SDSS J032015 2016 Van SDSS J091001.63164820.0
3.120 SDSS J113551 2017 Van, Mdy SDSS J113551.09532246.2
3.121 SDSS J115207 2009 Kato et al. (2010) SDSS J115207.00404947.8
2017 Mdy, KU, LCO, Ioh, DPV,
Kis
3.122 SDSS J131432 2017 Mdy, Van SDSS J131432.10444138.7
3.123 SDSS J153015 2017 Van SDSS J153015.04094946.3
3.124 SDSS J155720 2016 HaC, Kis SDSS J155720.75180720.2
SDSS J173047 2016 K. Isogai et al. in preparation SDSS J173047.59554518.5
3.125 SSS J134850 2016 MLF, HaC SSS J134850.1310835
3.126 TCP J013758 2016 Kis, IMi, Ioh, RPc, Shu, TCP J013758924951055
CRI, Rui, Trt
3.127 TCP J180018 2016 HaC, Nel, SPE TCP J180018543533149
Table 1: List of Superoutbursts (continued).
Object Right Ascention Declination Source SDSS Gaia G GALEX NUV
ASASSN-13ak \timeform17h 48m 27.87s \timeform+50D 50’ 39.8” Gaia 19.89(2) 19.06
ASASSN-13al \timeform19h 32m 06.39s \timeform+67D 27’ 40.4” GSC2.3.2 21.5(4)
ASASSN-13bc \timeform18h 02m 22.44s \timeform+45D 52’ 44.6” Gaia 19.53(2) 18.40 19.4(1)
ASASSN-13bj \timeform16h 00m 20.52s \timeform+70D 50’ 07.2” Gaia 18.43
ASASSN-13bo \timeform01h 43m 54.23s \timeform+29D 01’ 03.8” SDSS 20.94(4) 21.8(2)
ASASSN-13cs \timeform17h 11m 38.40s \timeform+05D 39’ 51.0” Gaia 19.80 20.9(2)
ASASSN-13cz \timeform15h 27m 55.11s \timeform+63D 27’ 54.2” Gaia 18.94(1) 18.74
ASASSN-14gg \timeform18h 21m 38.61s \timeform+61D 59’ 04.0” Gaia 19.74 19.4(1)
ASASSN-15cr \timeform07h 34m 42.71s \timeform+50D 42’ 29.0” Gaia 19.33 20.2(1)
ASASSN-16da \timeform12h 56m 09.83s \timeform+62D 37’ 04.4” SDSS 21.55(5) 21.6(4)
ASASSN-16dk \timeform10h 20m 53.48s \timeform-86D 17’ 29.77” Gaia 20.41 19.31(7)
ASASSN-16ds \timeform18h 25m 09.96s \timeform-46D 20’ 17.9” ASAS-SN
ASASSN-16dz \timeform06h 42m 25.58s \timeform+08D 25’ 46.6” Gaia 19.10
ASASSN-16ez \timeform15h 31m 29.87s \timeform+21D 38’ 30.2” SDSS 21.28(4)
ASASSN-16fr \timeform16h 42m 51.80s \timeform-08D 52’ 41.0” SDSS 20.97(4)
ASASSN-16fu \timeform22h 14m 05.03s \timeform-09D 04’ 19.4” SDSS 21.64(7)
ASASSN-16gh \timeform18h 15m 57.62s \timeform-72D 40’ 38.1” ASAS-SN
ASASSN-16gj \timeform09h 59m 58.97s \timeform-19D 01’ 00.0” GSC2.3.2 21.3(3)
ASASSN-16gl \timeform18h 27m 16.25s \timeform-52D 47’ 44.1” ASAS-SN
ASASSN-16hi \timeform21h 38m 58.01s \timeform-73D 19’ 17.5” Gaia 18.86 20.9(2)
ASASSN-16ia \timeform20h 51m 59.24s \timeform+34D 49’ 46.1” Gaia
ASASSN-16ib \timeform14h 32m 03.74s \timeform-33D 08’ 13.9” IGSL 21.5(4)
ASASSN-16ik \timeform19h 27m 45.88s \timeform-67D 15’ 16.7” IGSL 21.8(5)
ASASSN-16is \timeform18h 31m 03.63s \timeform+11D 32’ 02.9” Gaia 20.36
ASASSN-16iu \timeform01h 43m 47.87s \timeform-70D 17’ 01.1” Gaia 19.99 20.39(9)
ASASSN-16iw \timeform00h 58m 11.10s \timeform-01D 07’ 50.9” SDSS 21.9(1)

source of the coordinates: 2MASS (2MASS All-Sky Catalog of Point Sources; Cutri et al. (2003)), ASAS-SN (ASAS-SN measurements), CRTS (CRTS measurements), Gaia (Gaia DR1, Gaia Collaboration (2016) and outburst detections), GSC2.3.2 (The Guide Star Catalog, Version 2.3.2, Lasker et al. (2007)), IGSL (The Initial Gaia Source List 3, Smart (2013)), IPHAS DR2 (INT/WFC Photometric H Survey, Witham et al. (2008)), SDSS (The SDSS Photometric Catalog, Release 9, Ahn et al. (2012)).

Table 2: Coordinates of objects without coordinate-based names.
Object Right Ascention Declination Source SDSS Gaia G GALEX NUV
ASASSN-16jb \timeform17h 50m 44.99s \timeform-25D 58’ 37.1” ASAS-SN
ASASSN-16jd \timeform18h 50m 33.33s \timeform-26D 50’ 40.8” ASAS-SN
ASASSN-16jk \timeform15h 40m 24.84s \timeform+23D 07’ 50.8” Gaia 20.73(3) 20.68 21.7(3)
ASASSN-16js \timeform00h 51m 19.17s \timeform-65D 57’ 17.0” Gaia 20.08 22.1(2)
ASASSN-16jz \timeform19h 18m 53.39s \timeform+79D 32’ 16.0” IGSL
ASASSN-16kg \timeform21h 36m 29.86s \timeform-25D 13’ 48.3” CRTS
ASASSN-16kx \timeform06h 17m 18.72s \timeform-49D 38’ 57.3” ASAS-SN
ASASSN-16le \timeform23h 34m 35.56s \timeform+54D 33’ 25.5” Gaia 18.83
ASASSN-16lj \timeform20h 15m 46.04s \timeform+75D 47’ 41.7” Gaia 20.99(5) 20.17 21.5(2)
ASASSN-16lo \timeform18h 08m 41.02s \timeform+46D 19’ 34.9” IGSL
ASASSN-16mo \timeform02h 56m 56.67s \timeform+49D 27’ 47.1” Gaia 20.19
ASASSN-16my \timeform07h 41m 08.46s \timeform-30D 03’ 17.9” Gaia 18.52
ASASSN-16ni \timeform05h 05m 00.32s \timeform+60D 45’ 53.7” ASAS-SN
ASASSN-16nq \timeform23h 22m 09.25s \timeform+39D 50’ 07.8” Gaia 19.10 21.1(3)
ASASSN-16nr \timeform07h 09m 49.33s \timeform-49D 09’ 03.6” GSC2.3.2
ASASSN-16nw \timeform01h 53m 49.09s \timeform+52D 52’ 05.1” IGSL
ASASSN-16ob \timeform06h 47m 18.89s \timeform-64D 37’ 07.3” Gaia
ASASSN-16oi \timeform06h 21m 32.38s \timeform-62D 58’ 15.6” GSC2.3.2 22.0(5)
ASASSN-16os \timeform08h 43m 05.59s \timeform-84D 53’ 45.6” GSC2.3.2
ASASSN-16ow \timeform06h 30m 47.05s \timeform+02D 39’ 31.4” IPHAS
ASASSN-17aa \timeform04h 23m 56.40s \timeform-74D 05’ 27.5” ASAS-SN
ASASSN-17ab \timeform10h 40m 51.25s \timeform-37D 03’ 30.2” Gaia
ASASSN-17az \timeform00h 15m 09.31s \timeform-69D 45’ 49.2” ASAS-SN
ASASSN-17bl \timeform12h 31m 50.86s \timeform-50D 25’ 07.4” ASAS-SN
ASASSN-17bm \timeform10h 55m 27.84s \timeform-48D 04’ 27.4” GSC2.3.2
ASASSN-17bv \timeform09h 08m 45.65s \timeform-62D 37’ 11.0” IGSL
ASASSN-17ce \timeform13h 24m 24.46s \timeform-54D 09’ 21.7” Gaia 18.52
ASASSN-17ck \timeform08h 30m 46.29s \timeform-28D 58’ 13.5” GSC2.3.2
ASASSN-17cn \timeform09h 31m 22.60s \timeform-35D 20’ 54.3” Gaia
ASASSN-17cx \timeform10h 59m 57.97s \timeform-11D 57’ 56.8” GSC2.3.2 20.8(2)
ASASSN-17dg \timeform16h 02m 33.49s \timeform-60D 32’ 50.3” 2MASS
ASASSN-17dq \timeform09h 01m 25.26s \timeform-59D 31’ 40.1” ASAS-SN
DDE 26 \timeform22h 03m 28.21s \timeform+30D 56’ 36.5” Gaia 19.61(1) 19.32
SBS 1108574 \timeform11h 11m 26.83s \timeform+57D 12’ 38.6” Gaia 19.22(1) 19.26 19.5(1)
Table 2: Coordinates of objects without coordinate-based names (continued).
Object Year (d) err err (d) err (d) Q
V1047 Aql 2016 0.073666 0.000054 0 14 C
BB Ari 2016 0.072491 0.000026 27 70 19.7 4.2 0.072179 0.000019 70 115 A
OY Car 2016 0.064653 0.000028 0 104 9.9 1.7 0.064440 0.000049 103 159 0.063121 B
HT Cas 2016 0.076333 0.000005 19 62 0.075886 0.000005 72 145 0.073647 A
GS Cet 2016 0.056645 0.000014 14 156 6.3 0.6 0.05597 AE
GZ Cet 2016 0.056702 0.000028 0 54 11.4 2.8 0.056409 0.000006 141 425 0.055343 B
AK Cnc 2016 0.067454 0.000030 0 76 0.0651 C
GZ Cnc 2017 0.092881 0.000022 32 91 0.9 4.9 0.092216 0.000291 91 113 0.08825 C
GP CVn 2016 0.064796 0.000027 17 96 9.5 2.5 0.062950 B
V1113 Cyg 2016 0.078848 0.000028 52 141 2.4 2.9 B
IX Dra 2016 0.066895 0.000045 0 92 4.7 4.6 C
IR Gem 2016 0.071090 0.000047 0 33 0.070633 0.000047 56 104 0.0684 C
IR Gem 2017 0.071098 0.000020 25 56 0.0684 C
NY Her 2016 0.075832 0.000043 0 42 0.075525 0.000051 49 114 B
V699 Oph 2016 0.070212 0.000096 0 28 C
V344 Pav 2016 0.079878 0.000031 0 76 8.8 2.7 CG
V893 Sco 2016 0.074666 0.000326 0 26 0.075961 C2
V493 Ser 2016 0.082730 0.000129 0 13 0.08001 C
V1389 Tau 2016 0.080456 0.000081 0 35 0.079992 0.000025 34 121 C
Interval used for calculating the period (corresponding to in section 3).
Unit .

References:

GZ Cet (Pretorius et al., 2004), AK Cnc (Arenas and Mennickent, 1998), GZ Cnc (Tappert and Bianchini, 2003), IR Gem (Feinswog et al., 1988), V493 Ser (Thorstensen et al., 2015), HV Vir (Patterson et al., 2003), SBS 1108 (Kato et al., 2013), OY Car, GS Cet, GP CVn, V893 Sco, ASASSN-16da, ASASSN-16fu, ASASSN-16ia, ASASSN-16is, ASASSN-16jb, ASASSN-16js, ASASSN-16lo, ASASSN-16oi, ASASSN-16os, ASASSN-17bl, ASASSN-17cn, MASTER J042609, MASTER J220559, SDSS J115207 (this work)

Data quality and comments. A: excellent, B: partial coverage or slightly low quality, C: insufficient coverage or observations with large scatter, G: denotes global , M: observational gap in middle stage, U: uncertainty in alias selection, 2: late-stage coverage, the listed period may refer to , a: early-stage coverage, the listed period may be contaminated by stage A superhumps, E: refers to the period of early superhumps, P: refers to a shorter stable periodicity recorded in outburst.

Table 3: Superhump Periods and Period Derivatives
Object Year err err err Q
HV Vir 2016 0.058244 0.000009 31 227 3.1 0.4 0.057069 A
NSV 2026 2016b 0.069906 0.000022 0 13 C
NSV 14681 2016 0.090063 0.000008 0 77 0.5 0.8 C
1RXS J161659 2016 0.071370 0.000063 0 43 0.071063 0.000054 56 74 C
1RXS J161659 2016b 0.071229 0.000056 0 58 C
ASASSN-13al 2016 0.0783 0.0002 0 3 C
ASASSN-13bc 2015 0.070393 0.000118 0 16 C
ASASSN-13bc 2016 0.070624 0.000100 0 39 0.070101 0.000046 39 85 C
ASASSN-13bj 2016 0.072553 0.000047 0 21 0.071918 0.000053 23 44 C
ASASSN-13bo 2016 0.071860 0.000025 0 41 CU
ASASSN-13cs 2016 0.077105 0.000098 0 20 C
ASASSN-13cz 2016 0.080135 0.000044 0 13 0.079496 0.000368 62 76 C
ASASSN-14gg 2016 0.059311 0.000035 0 89 13.1 2.9 B
ASASSN-15cr 2017 0.061554 0.000021 16 149 7.8 1.5 0.061260 0.000005 146 217 B
ASASSN-16da 2016 0.057344 0.000024 10 175 7.5 0.9 0.056994 0.000062 203 239 0.05610 BE
ASASSN-16dk 2016 0.075923 0.000047 0 67 C
ASASSN-16ds 2016 0.067791 0.000027 33 195 7.1 0.6 0.067228 0.000051 B
ASASSN-16dt 2016 0.064507 0.000005 62 214 1.6 0.5 0.064197 AE
ASASSN-16dz 2016 0.066260 0.000170 0 16 CU
ASASSN-16eg 2016 0.077880 0.000003 15 106 10.4 0.8 0.077589 0.000007 120 181 0.075478 AE
ASASSN-16ez 2016 0.057621 0.000017 0 77 2.1 2.9 C
ASASSN-16fr 2016 0.071394 0.000144 0 35 C
ASASSN-16fu 2016 0.056936 0.000013 35 195 4.6 0.6 0.05623 BE
ASASSN-16gh 2016 0.061844 0.000017 16 100 6.7 2.7 B
ASASSN-16gj 2016 0.057997 0.000022 74 208 7.0 1.0 B
ASASSN-16gl 2016 0.055834 0.000010 0 118 1.6 1.2 B
ASASSN-16hg 2016 0.062371 0.000014 15 115 0.6 1.7 B
ASASSN-16hi 2016 0.059040 0.000024 0 121 8.6 1.5 0.058674 0.000023 118 188 B
ASASSN-16hj 2016 0.055644 0.000041 20 145 11.3 1.3 0.055465 0.000036 144 324 0.05499 BE
Table 3: Superhump Periods and Period Derivatives (continued)
Object Year err err err Q
ASASSN-16ib 2016 0.058855 0.000015 47 144 2.2 2.0 C
ASASSN-16ik 2016 0.064150 0.000018 33 126 1.0 2.1 B
ASASSN-16is 2016 0.058484 0.000015 0 105 4.2 1.7 0.05762 CE
ASASSN-16iu 2016 0.058720 0.000062 0 104 26.7 3.3 0.058661 0.000300 34 53 C
ASASSN-16iw 2016 0.065462 0.000039 42 153 10.0 3.2 0.06495 BE
ASASSN-16jb 2016 0.064397 0.000021 30 193 5.9 0.7 0.064170 0.000075 193 232 0.06305 AE
ASASSN-16jd 2016 0.058163 0.000039 34 223 7.9 0.6 0.057743 0.000159 223 258 B
ASASSN-16jk 2016 0.061391 0.000028 16 146 8.6 1.3 C
ASASSN-16js 2016 0.060934 0.000015 48 173 4.9 1.0 0.06034 AE
ASASSN-16jz 2016 0.060936 0.000014 0 51 C
ASASSN-16kg 2016 0.100324 0.000189 0 30 CU
ASASSN-16kx 2016 0.080760 0.000036 0 54 6.4 6.5 0.080536 0.000041 79 153 C
ASASSN-16le 2016 0.0808 0.0013 0 2 C
ASASSN-16lj 2016 0.0857 0.0004 0 2 C
ASASSN-16lo 2016 0.054608 0.000036 38 86 0.05416 CE
ASASSN-16mo 2016 0.066477 0.000016 0 84 3.9 2.3 C
ASASSN-16my 2016 0.087683 0.000049 23 92 3.0 5.7 C
ASASSN-16ni 2016 0.115242 0.000442 0 11 CU
ASASSN-16nq 2016 0.079557 0.000045 0 39 0.0 9.3 0.079069 0.000035 59 161 B
ASASSN-16nr 2016 0.082709 0.000080 0 59 19.8 10.1 CG
ASASSN-16nw 2016 0.072813 0.000045 0 43 C
ASASSN-16ob 2016 0.057087 0.000014 52 249 1.8 0.5 B
ASASSN-16oi 2016 0.056241 0.000017 12 122 5.0 1.7 0.05548 BE
ASASSN-16os 2016 0.054992 0.000013 39 168 0.3 1.4 0.05494 BE
ASASSN-16ow 2016 0.089311 0.000052 0 40 0.088866 0.000022 55 102 B
ASASSN-17aa 2017 0.054591 0.000013 0 182 2.8 0.3 0.05393 BE
ASASSN-17ab 2017 0.070393 0.000016 15 88 3.6 2.5 C
ASASSN-17az 2017 0.056492 0.000038 0 36 CU
ASASSN-17bl 2017 0.055367 0.000010 53 237 3.6 0.6 0.05467 CE
Table 3: Superhump Periods and Period Derivatives (continued)
Object Year err err err Q
ASASSN-17bm 2017 0.082943 0.000056 0 53 C
ASASSN-17bv 2017 0.082690 0.000021 12 52 6.3 3.9 0.082489 0.000048 58 103 B
ASASSN-17ce 2017 0.081293 0.000111 0 22 0.080796 0.000042 21 139 C
ASASSN-17ck 2017 0.083 0.001 0 1 C
ASASSN-17cn 2017 0.053991 0.000014 0 137 5.6 0.8 0.05303 BE
ASASSN-17cx 2017 0.0761 0.0007 0 2 C
ASASSN-17dg 2017 0.066482 0.000046 0 36 C
ASASSN-17dq 2017 0.058052 0.000034 0 93 9.3 3.5 0.057660 0.000076 90 142 C
CRTS J000130 2016 0.094749 0.000066 0 63 C
CRTS J023638 2016 0.073703 0.000057 0 42 0.073504 0.000053 40 80 C
CRTS J033349 2016 0.076159 0.000049 0 60 C
CRTS J082603 2017 0.0719 0.0004 0 1 C
CRTS J085113 2016 0.08750 0.00009 0 1 C
CRTS J085603 2016 0.060043 0.000193 0 18 C
CRTS J164950 2016 0.064905 0.000091 0 61 C
CSS J044637 2017 0.093 0.001 0 1 C
CSS J062450 2017 0.077577 0.000094 0 14 C
DDE 26 2016 0.088804 0.000067 0 44 C
MASTER J021315 2016 0.105124 0.000252 10 21 C
MASTER J030205 2016 0.061553 0.000022 1 96 8.4 2.5 B
MASTER J042609 2016 0.067624 0.000016 0 64 6.4 2.7 0.067221 0.000051 64 122 0.065502 B
MASTER J043220 2017 0.0640 0.0006 0 1 C
MASTER J043915 2016 0.062428 0.000045 0 112 C
MASTER J054746 2016 0.0555 0.0004 0 3 C
MASTER J055348 2017 0.0750 0.0001 0 24 CU
MASTER J064725 2016 0.067584 0.000020 0 108 1.2 3.5 CG
MASTER J065330 2017 0.064012 0.000167 0 13 C
MASTER J075450 2017 0.0664 0.0050 0 1 C
MASTER J150518 2017 0.071145 0.000125 0 56 29.5 1.0 CGU
Table 3: Superhump Periods and Period Derivatives (continued)
Object Year err err err Q
MASTER J151126 2016 0.058182 0.000016 16 171 4.5 0.6 C
MASTER J055845 2016 0.058070 0.000081 0 19 C2
MASTER J162323 2016 0.09013 0.00007 0 4 Ca
MASTER J165153 2017 0.071951 0.000079 0 31 C
MASTER J174816 2016 0.083328 0.000120 0 21 CU
MASTER J191841 2016 0.022076 0.000007 0 51 B
MASTER J220559 2016 0.061999 0.000067 0 83 28.4 6.5 0.061434 0.000078 81 116 0.061286 C
OT J002656 2016 0.132240 0.000054 30 112 16.4 1.6 B
SBS 1108 2016 0.039051 0.000008 0 72 0.038449 CP
SDSS J032015 2016 0.073757 0.000028 0 137 2.5 4.2 CG
SDSS J091001 2017 0.0734 0.0002 0 2 C
SDSS J113551 2017 0.0966 0.0001 0 18 CU
SDSS J115207 2009 0.070028 0.000088 0 68 0.067750 CG
SDSS J115207 2017 0.070362 0.000044 0 52 0.069914 0.000019 52 131 0.067750 B
SDSS J131432 2017 0.065620 0.000034 0 55 18.3 8.6 C
SDSS J153015 2017 0.075241 0.000039 0 41 C
SDSS J155720 2016 0.085565 0.000131 0 29 C
SDSS J173047 2016 0.024597 0.000007 0 329 0.8 0.3 B
SSS J134850 2016 0.084534 0.000017 0 80 3.0 1.6 CG
TCP J013758 2016 0.061692 0.000024 31 142 12.6 0.8 0.061408 0.000032 140 208 B
TCP J180018 2016 0.058449 0.000024 26 233 5.7 0.7 B
Table 3: Superhump Periods and Period Derivatives (continued)

3 Individual Objects

3.1 V1047 Aquilae

V1047 Aql was discovered as a dwarf nova (S 8191) by Hoffmeister (1964). Hoffmeister (1964) reported a blue color in contrast to the nearby stars. Mason and Howell (2003) obtained a spectrum typical for a quiescent dwarf nova. According to R. Stubbings, the observation by Greg Bolt during the 2005 August outburst detected superhumps, and the superhump period was about 0.074 d (see Kato et al. (2012b)). The object shows rather frequent outbursts (approximately once in 50 d), and a number of outbursts have been detected mainly by R. Stubbings visually since 2004.

The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 15.0 on July 8. Subsequent observations detected superhumps (vsnet-alert 19974; figure 2). Using the 2005 period, we could identify two maxima on two nights: =0, BJD 2457581.3853(7) (=74) and =14, BJD 2457582.4190(11) (=72). The period given in table 3 is determined by the PDM method.

Although observations are not sufficient, visual observations by R. Stubbings suggest a supercycle of 90 d, which would make V1047 Aql one of ordinary SU UMa-type dwarf novae with shortest supercycles.

\FigureFile

(85mm,110mm)v1047aqlshpdm.eps

Figure 2: Superhumps in V1047 Aql (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.

3.2 BB Arietis

This object was discovered as a variable star (Ross 182, NSV 907) on a plate on 1926 November 26 (Ross, 1927). The dwarf nova-type nature was suspected by the association with an ROSAT source (Kato, vsnet-chat 3317). The SU UMa-type nature was confirmed during the 2004 superoutburst. For more information, see Kato et al. (2014a).

The 2016 superoutburst was detected by P. Schmeer at a visual magnitude of 13.2 on October 30 (vsnet-alert 20273). Thanks to the early detection (this visual detection was 1 d earlier than the ASAS-SN detection), stage A growing superhumps were detected (vsnet-alert 20292). At the time of the initial observation, the object was fading from a precursor outburst. Further observations recorded development of superhumps clearly (vsnet-alert 20312, 20321). The times of superhump maxima are listed in table 4. There were clear stages A–C (figure 3). The 2013 superoutburst had a separate precursor outburst and a comparison of the diagrams suggests a difference of 44 cycle count from that used in Kato et al. (2014a). The value suggests that superhumps during the 2013 superoutburst evolved 3 d after the precursor outburst.

\FigureFile

(88mm,70mm)bbaricomp2.eps

Figure 3: Comparison of diagrams of BB Ari between different superoutbursts. A period of 0.07249 d was used to draw this figure. Approximate cycle counts () after the starts of outbursts were used. The definition is different from the corresponding figure in Kato et al. (2014a). The 2013 superoutburst had a separate precursor outburst and the cycle count is different by 44 from that used in Kato et al. (2014a). The value suggests that superhumps during the 2013 superoutburst evolved 3 d after the precursor outburst. Since the start of the 2004 superoutburst was not well constrained, we shifted the diagram to best fit the 2016 one.
max error
0 57692.5399 0.0017 0. 0323 194
1 57692.6138 0.0024 0. 0310 72
12 57693.4416 0.0003 0. 0008 129
13 57693.5156 0.0003 0. 0008 125
24 57694.3177 0.0003 0. 0051 188
25 57694.3910 0.0002 0. 0059 162
26 57694.4636 0.0002 0. 0061 182
27 57694.5368 0.0002 0. 0068 194
28 57694.6085 0.0002 0. 0059 80
29 57694.6808 0.0002 0. 0057 153
39 57695.4037 0.0004 0. 0035 80
40 57695.4767 0.0004 0. 0040 81
41 57695.5474 0.0005 0. 0021 69
51 57696.2726 0.0003 0. 0022 82
54 57696.4924 0.0006 0. 0045 42
55 57696.5648 0.0005 0. 0043 115
56 57696.6367 0.0007 0. 0038 128
57 57696.7070 0.0015 0. 0015 100
62 57697.0725 0.0006 0. 0044 69
63 57697.1432 0.0005 0. 0026 48
64 57697.2184 0.0011 0. 0054 20
65 57697.2899 0.0012 0. 0044 41
67 57697.4356 0.0006 0. 0050 47
70 57697.6541 0.0013 0. 0060 75
71 57697.7259 0.0012 0. 0053 93
72 57697.7988 0.0011 0. 0057 113
74 57697.9384 0.0005 0. 0002 134
75 57698.0160 0.0004 0. 0053 153
76 57698.0874 0.0009 0. 0042 216
77 57698.1599 0.0004 0. 0042 242
78 57698.2327 0.0003 0. 0045 241
79 57698.3027 0.0006 0. 0020 133
82 57698.5219 0.0008 0. 0037 23
83 57698.5939 0.0004 0. 0031 86
84 57698.6669 0.0003 0. 0036 77
85 57698.7364 0.0011 0. 0006 124
86 57698.8096 0.0016 0. 0012 71
88 57698.9535 0.0007 0. 0001 135
89 57699.0251 0.0005 0. 0008 135
90 57699.0947 0.0005 0. 0037 127
91 57699.1687 0.0005 0. 0022 135
92 57699.2430 0.0029 0. 0004 49
97 57699.6023 0.0007 0. 0036 33
98 57699.6755 0.0003 0. 0030 74
99 57699.7472 0.0011 0. 0038 111
100 57699.8208 0.0015 0. 0027 83
103 57700.0378 0.0004 0. 0033 129
104 57700.1071 0.0006 0. 0065 127
105 57700.1812 0.0005 0. 0048 134
109 57700.4683 0.0014 0. 0078 40
113 57700.7578 0.0011 0. 0084 144
114 57700.8295 0.0011 0. 0091 90
115 57700.9016 0.0004 0. 0096 67
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 4: Superhump maxima of BB Ari (2016)

3.3 V391 Camelopardalis

This object (=1RXS J053234.9624755) was discovered as a dwarf nova by Bernhard et al. (2005). Kapusta and Thorstensen (2006) provided a radial-velocity study and yielded an orbital period of 0.05620(4) d. The SU UMa-type nature was established during the 2005 superoutburst (Imada et al., 2009). See Kato et al. (2009) for more history. The 2009 superoutburst was also studied in Kato et al. (2010).

The 2017 superoutburst was detected by P. Schmeer at a visual magnitude of 11.4 and also by the ASAS-SN team at =11.82 on March 15. Single superhump was recorded at BJD 2457829.3171(2) (=236). Although there were observations on three nights immediately after the superoutburst, we could neither detect superhump nor orbital periods.

3.4 OY Carinae

See Kato et al. (2015a) for the history of this well-known eclipsing SU UMa-type dwarf nova. The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 11.6 on April 2 (vsnet-alert 19676). Due to an accidental delay in the start of observations, the earliest time-resolved CCD observations were obtained on April 3 (vsnet-alert 19706). On that night, superhumps (likely in the growing phase) unfortunately overlapped with eclipses (figure 4, upper panel). Distinct superhumps were recorded on April 4 (vsnet-alert 19692; figure 4, middle panel). A further analysis suggested that stage A superhumps escaped detection before April 4 (due to the lack of observations and overlapping eclipses). At the time of April 4, the superhumps were already likely stage B (table 5, maxima outside eclipses). We could, however, confirmed a positive for stage B superhumps (cf. figure 5), whose confirmation had been still awaited (cf. Kato et al. (2015a)).

The combined data used in Kato et al. (2015a) and new observations, we have obtained the eclipse ephemeris for the use of defining the orbital phases in this paper using the MCMC analysis (Kato et al., 2013):

(1)

The epoch corresponds to the center of the entire observation. The mean period, however, did not show a secular decrease (e.g. Han et al. (2015); Kato et al. (2015a)). It may be that period changes in this system are sporadic and do not reflect the secular CV evolution.

\FigureFile

(85mm,110mm)oycarshlc.eps

Figure 4: Eclipses and superhumps in OY Car in the earliest phase (2016). The data were binned to 0.001 d. During the first run (upper panel), eclipses were very shallow since they overlapped with superhumps.
\FigureFile

(85mm,70mm)oycarcomp2.eps

Figure 5: Comparison of diagrams of OY Car between different superoutbursts. A period of 0.06465 d was used to draw this figure. Approximate cycle counts () after the starts of outbursts were used. The 2015 superoutburst with a separate precursor outburst was shifted by 15 cycles to best match the others. Since the start of the 2016 superoutburst was not well constrained, the values were shifted by 45 cycles to best match the others. This shift suggests that the actual start of the 2016 superoutburst occurred 2 d before the initial detection.
max error phase
0 57482.8885 0.0006 0. 0027 0.27 47
1 57482.9553 0.0006 0. 0049 0.33 49
18 57484.0441 0.0007 0. 0047 0.58 36
19 57484.1113 0.0006 0. 0022 0.65 33
20 57484.1737 0.0006 0. 0044 0.63 33
57 57486.5651 0.0009 0. 0037 0.52 25
58 57486.6311 0.0012 0. 0023 0.56 24
72 57487.5391 0.0009 0. 0012 0.95 15
73 57487.5998 0.0022 0. 0027 0.91 19
80 57488.0572 0.0023 0. 0024 0.16 29
88 57488.5735 0.0015 0. 0018 0.34 21
89 57488.6375 0.0009 0. 0012 0.35 15
103 57489.5472 0.0010 0. 0063 0.76 21
104 57489.6123 0.0010 0. 0068 0.80 20
142 57492.0563 0.0023 0. 0044 0.51 39
143 57492.1281 0.0063 0. 0027 0.65 33
150 57492.5795 0.0020 0. 0018 0.80 17
158 57493.0907 0.0017 0. 0039 0.90 28
159 57493.1556 0.0083 0. 0036 0.93 14
BJD2400000.
Against max .
Orbital phase.
Number of points used to determine the maximum.
Table 5: Superhump maxima of OY Car (2016)

3.5 GS Ceti

This object (SDSS J005050.88000912.6) was selected as a CV during the course of the SDSS (Szkody et al., 2005). The spectrum was that of a quiescent dwarf nova. Southworth et al. (2007) obtained 8 hr of photometry giving a suspected orbital period of 76 min.

Although there were no secure outburst record in the past, the object was detected in bright outburst on 2016 November 9 at =13.0 by the ASAS-SN team (vsnet-alert 20328). Subsequent observations detected early superhumps (vsnet-alert 20334, 20342). Although the profile was not doubly peaked as in many WZ Sge-type dwarf novae (cf. Kato (2015)), we consider the signal to be that of early superhumps since it was seen before the appearance of ordinary superhumps and the period was close to the suggested orbital period by quiescent photometry (figure 6). The object started to show ordinary superhumps on November 17 (vsnet-alert 20368, 20381, 20395, 20404; figure 7). The times of superhump maxima are listed in table 6. There were clear stages A and B.

The best period of early superhumps by the PDM method was 0.05597(3) d. Combined with the period of stage A superhumps, the of 0.0288(8) corresponds to =0.078(2). Although the object is a WZ Sge-type dwarf nova, it is not a very extreme one as judged from the relatively large of stage B superhumps and the lack of the feature of an underlying white dwarf in the optical spectra in quiescence (Szkody et al. (2005); Southworth et al. (2007)). Although there were some post-superoutburst observations, the quality of the data was not sufficient to detect superhumps.

\FigureFile

(85mm,110mm)gsceteshpdm.eps

Figure 6: Early superhumps in GS Cet (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
\FigureFile

(85mm,110mm)gscetshpdm.eps

Figure 7: Ordinary superhumps in GS Cet (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
max error
0 57709.1297 0.0005 0. 0088 62
7 57709.5380 0.0008 0. 0029 12
8 57709.5897 0.0008 0. 0021 19
9 57709.6481 0.0020 0. 0004 15
14 57709.9371 0.0005 0. 0054 138
15 57709.9942 0.0004 0. 0059 191
16 57710.0499 0.0002 0. 0049 158
17 57710.1048 0.0002 0. 0032 222
18 57710.1611 0.0003 0. 0027 143
25 57710.5575 0.0006 0. 0026 21
26 57710.6147 0.0007 0. 0032 21
27 57710.6706 0.0009 0. 0024 23
39 57711.3486 0.0010 0. 0005 100
40 57711.4036 0.0002 0. 0011 322
43 57711.5759 0.0007 0. 0012 22
44 57711.6342 0.0014 0. 0029 14
52 57712.0830 0.0010 0. 0016 59
73 57713.2710 0.0006 0. 0033 28
74 57713.3268 0.0008 0. 0041 24
78 57713.5523 0.0015 0. 0052 21
79 57713.6095 0.0013 0. 0047 20
80 57713.6660 0.0005 0. 0049 23
89 57714.1783 0.0031 0. 0025 18
90 57714.2345 0.0007 0. 0030 93
91 57714.2918 0.0006 0. 0023 70
92 57714.3491 0.0005 0. 0016 31
102 57714.9150 0.0010 0. 0023 150
103 57714.9737 0.0004 0. 0002 179
107 57715.1981 0.0005 0. 0024 32
108 57715.2538 0.0004 0. 0034 33
109 57715.3118 0.0005 0. 0020 57
110 57715.3695 0.0006 0. 0010 60
113 57715.5381 0.0039 0. 0023 13
114 57715.5945 0.0011 0. 0026 21
115 57715.6503 0.0018 0. 0035 20
131 57716.5634 0.0011 0. 0032 22
132 57716.6198 0.0031 0. 0029 13
133 57716.6754 0.0038 0. 0019 14
140 57717.0650 0.0019 0. 0052 97
149 57717.5867 0.0053 0. 0066 22
150 57717.6428 0.0063 0. 0061 12
155 57717.9271 0.0017 0. 0072 50
156 57717.9815 0.0021 0. 0049 81
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 6: Superhump maxima of GS Cet (2016)

3.6 GZ Ceti

This object was originally selected as a CV (SDSS J013701.06091234.9) during the course of the SDSS (Szkody et al., 2003). Szkody et al. (2003) obtained spectra showing broad absorption surrounding the emission lines of H and higher members of the Balmer series. The object showed the TiO bandheads of an M dwarf secondary. A radial-velocity study by Szkody et al. (2003) suggested an orbital period of 80–86 min. There was a superoutburst in 2003 December and Pretorius et al. (2004) reported the orbital and superhump periods of 79.71(1) min and 81.702(7) min, respectively. Pretorius et al. (2004) reported the period variation of superhumps, which can be now interpreted as stages B and C. Pretorius et al. (2004) suggested that this object has a low mass-transfer rate. The same superoutburst was studied by Imada et al. (2006), who reported the superhump period of 0.056686(12) d. Imada et al. (2006) noticed the unusual presence of the TiO bands for this short- object and discussed that the secondary should be luminous. Ishioka et al. (2007) obtained an infrared spectrum dominated by the secondary component. Ishioka et al. (2007) suggested that the evolutionary path of GZ Cet is different from that of ordinary CVs, and that it is a candidate of a member of EI Psc-like systems. EI Psc-like systems are CVs below the period minimum showing hydrogen (likely somewhat reduced in abundance) in their spectra (cf. Thorstensen et al. (2002); Uemura et al. (2002); Littlefield et al. (2013)) and are consider to be evolving towards AM CVn-type objects. Superhump observations during the superoutbursts in 2009 and 2011 were also reported in Kato et al. (2009) and Kato et al. (2013), respectively.

The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 12.6 on December 18 (vsnet-alert 20493). The ASAS-SN team also recorded the outburst at =12.66 on December 17. This superoutburst was observed in its relatively late phase to the post-superoutburst phase (vsnet-alert 20594). There was also a post-superoutburst rebrightening on 2017 January 15 (vsnet-alert 20569). The times of superhump maxima are listed in table 7. The times after =266 represent post-superoutburst superhumps. The maxima for 54 were stage B superhumps and “textbook” stage C superhumps continued even during the post-superoutburst phase without a phase jump as in traditional late superhumps (figure 8).

\FigureFile

(88mm,70mm)akcnccomp2.eps

Figure 8: Comparison of diagrams of GZ Cet between different superoutbursts. A period of 0.05672 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57743.0047 0.0001 0. 0090 108
1 57743.0605 0.0001 0. 0097 121
2 57743.1185 0.0013 0. 0082 27
17 57743.9670 0.0001 0. 0070 121
18 57744.0226 0.0002 0. 0079 117
19 57744.0801 0.0003 0. 0069 80
54 57746.0667 0.0005 0. 0027 86
141 57750.9873 0.0003 0. 0088 72
159 57752.0029 0.0002 0. 0077 121
160 57752.0582 0.0005 0. 0064 67
177 57753.0200 0.0003 0. 0079 120
193 57753.9237 0.0002 0. 0079 98
194 57753.9799 0.0002 0. 0076 120
195 57754.0336 0.0002 0. 0047 116
212 57754.9954 0.0004 0. 0062 78
213 57755.0499 0.0006 0. 0043 103
229 57755.9562 0.0003 0. 0068 120
230 57756.0114 0.0004 0. 0055 118
247 57756.9729 0.0003 0. 0067 121
248 57757.0278 0.0004 0. 0051 120
266 57758.0403 0.0004 0. 0008 49
299 57759.9016 0.0018 0. 0020 21
300 57759.9609 0.0008 0. 0009 43
301 57760.0189 0.0006 0. 0023 42
371 57763.9655 0.0008 0. 0052 27
372 57764.0213 0.0010 0. 0058 38
424 57766.9494 0.0014 0. 0152 42
425 57767.0057 0.0015 0. 0153 21
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 7: Superhump maxima of GZ Cet (2016)

3.7 AK Cancri

AK Cnc was discovered as a short-period variable star (AN 77.1933) with a photographic range of 14 to fainter than 15.5 (Morgenroth, 1933). Morgenroth (1933) detected two maxima on 48 plates between JD 2425323 and 2426763. Tsesevich (1967) classified this object to be a U Gem-type variable without a particular remark. Williams (1983) reported a G-type spectrum unlike for a CV. The identification was later found to be incorrect (Howell et al. (1990); Wenzel (1993b)). The identification chart by Vogt and Bateson (1982) was correct. Amateur observers, particularly AAVSO and VSOLJ observers, made regular monitoring since 1986 and detected several outbursts. Time-resolved CCD observation by Howell et al. (1990) recorded a declining part of an outburst. Szkody and Howell (1992) obtained a spectrum in quiescence, which was characteristic to a dwarf nova. Wenzel (1993b) and Wenzel (1993a) reported observations using photographic archival materials and discussed outburst properties. Wenzel (1993b) also gave a summary of confusing history of the identification of this object.

Kato (1994) was the first to identify this object to be an SU UMa-type dwarf nova by observing the 1992 superoutburst. Mennickent et al. (1996) reported another superoutburst in 1995. The orbital period was spectroscopically measured to be 0.0651(2) d (Arenas and Mennickent, 1998). Kato et al. (2009) provided analyses of the 1999 and 2003 superoutbursts. Kato et al. (2013) further reported observations of the 2012 superoutburst.

The 2016 superoutburst was detected at a visual magnitude of 13.5 by G. Poyner on April 5. The times of superhump maxima are listed in table 8. Due to the rather poor coverage, we could not determine for stage B although the distinction between stages B and C was clear. Although positive for stage B is expected for this , it still awaits better observations (figure 9).

\FigureFile

(88mm,70mm)akcnccomp2.eps

Figure 9: Comparison of diagrams of AK Cnc between different superoutbursts. A period of 0.06743 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57485.9732 0.0025 0. 0043 17
1 57486.0453 0.0003 0. 0004 38
2 57486.1121 0.0010 0. 0002 24
15 57486.9901 0.0005 0. 0014 28
16 57487.0571 0.0006 0. 0010 38
60 57490.0249 0.0007 0. 0025 38
75 57491.0388 0.0009 0. 0053 21
76 57491.0993 0.0033 0. 0017 22
104 57492.9853 0.0018 0. 0033 26
105 57493.0550 0.0031 0. 0011 26
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 8: Superhump maxima of AK Cnc (2016)

3.8 GZ Cancri

GZ Cnc was discovered by K. Takamizawa as a variable star (=TmzV34). The object was confirmed as a dwarf nova (Kato et al. (2001b); Kato et al. (2002a)). Tappert and Bianchini (2003) obtained the orbital period of 0.08825(28) d by radial-velocity observations. The SU UMa-type nature was established during the 2010 (Kato et al., 2010). See Kato et al. (2014a) for more information.

The 2017 superoutburst was detected by R. Stubbings at a visual magnitude of 13.0 on February 2 and on the same night at 12.5 mag by T. Horie. Subsequent observations detected growing superhumps on February 3 and 4. Superhumps grew further on February 6 (vsnet-alert 20642). The times of superhump maxima are listed in table 9. Thanks to the early detection of the outburst, stage A superhumps were clearly detected (figure 10). The for stage A superhumps [0.081(3)] corresponds to =0.27(2).

\FigureFile

(88mm,70mm)gzcnccomp3.eps

Figure 10: Comparison of diagrams of GZ Cnc between different superoutbursts. A period of 0.09290 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57788.0546 0.0015 0. 0381 208
11 57789.1105 0.0007 0. 0062 120
32 57791.0878 0.0002 0. 0162 156
33 57791.1809 0.0003 0. 0162 185
34 57791.2760 0.0007 0. 0182 88
48 57792.5748 0.0008 0. 0138 19
91 57796.5686 0.0028 0. 0047 33
102 57797.5774 0.0024 0. 0104 23
113 57798.5974 0.0030 0. 0145 34
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 9: Superhump maxima of GZ Cnc (2017)

3.9 GP Canum Venaticorum

This object was originally selected as a CV (SDSS J122740.83513925.0) during the course of the SDSS (Szkody et al., 2006). Szkody et al. (2006) obtained a spectrum showing an underlying white dwarf. Littlefair et al. (2008) clarified that this object is an eclipsing dwarf nova with a short orbital period. The object underwent the first-recorded superoutburst in 2007 June. This 2007 superoutburst was analyzed by Shears et al. (2008) and Kato et al. (2009). Kato et al. (2012a) reported on the 2011 superoutburst and provided a corrected eclipse ephemeris. Savoury et al. (2011) reported the orbital parameters (including ) by modeling the eclipse profile. Although Zengin Çamurdan et al. (2010) suspected cyclic variation of eclipses, their result was doubtful due to the very low time-resolution of observations and very few points on the diagram.

The 2016 superoutburst was detected by the ASAS-SN team at =15.29 on April 25. Both superhumps and eclipses were recorded (vsnet-alert 19778). Using the combined data of 2007, 2011 and 2016 observations, we have refined the eclipse ephemeris by the MCMC modeling (Kato et al., 2013):

(2)

The epoch in Littlefair et al. (2008) corresponds to an value of 0.00168 d against this ephemeris. The ephemeris in Littlefair et al. (2008) predicts eclipses to occur 0.0096 d later than our actual observations in 2016.

The times of superhump maxima during the 2016 superoutburst are listed in table 10. Stage B with a positive and a transition to stage C superhumps were recorded (see also figure 11).

\FigureFile

(85mm,70mm)gpcvncomp2.eps

Figure 11: Comparison of diagrams of GP CVn between different superoutbursts. A period of 0.05828 d was used to draw this figure. Approximate cycle counts () after the appearance of superhumps were used. Note that this treatment is different from the corresponding figure in Kato et al. (2012a). Since the 2007 observation apparently caught the early part of stage A, we set the initial superhump of 2007 to be =0 in this figure. Other superoutbursts have been shifted to best match the 2007 one. The shift value suggests that the ASAS-SN detection of the 2016 superoutburst occurred 13 cycles after the appearance of superhumps.
max error phase
0 57505.4014 0.0016 0. 0043 0.95 20
1 57505.4740 0.0004 0. 0036 0.10 41
2 57505.5333 0.0033 0. 0016 0.05 21
17 57506.5052 0.0002 0. 0005 0.49 140
18 57506.5681 0.0002 0. 0012 0.48 143
29 57507.2793 0.0003 0. 0012 0.78 43
30 57507.3439 0.0005 0. 0013 0.81 47
46 57508.3822 0.0007 0. 0027 0.30 63
47 57508.4425 0.0004 0. 0017 0.26 135
48 57508.5079 0.0003 0. 0009 0.30 117
49 57508.5702 0.0003 0. 0032 0.29 103
94 57511.4920 0.0006 0. 0094 0.70 59
95 57511.5571 0.0004 0. 0099 0.74 57
96 57511.6217 0.0010 0. 0098 0.76 39
120 57513.1625 0.0019 0. 0010 0.24 54
121 57513.2235 0.0029 0. 0046 0.21 41
123 57513.3460 0.0031 0. 0115 0.15 24
124 57513.4216 0.0005 0. 0005 0.36 54
125 57513.4850 0.0017 0. 0018 0.36 61
126 57513.5502 0.0008 0. 0012 0.40 63
BJD2400000.
Against max .
Orbital phase.
Number of points used to determine the maximum.
Table 10: Superhump maxima of GP CVn (2016)

3.10 V337 Cygni

V337 Cyg was discovered as a long-period variable (AN 101.1928). The dwarf nova-type nature was confirmed in 1996. The SU UMa-type nature was established during the 2006 superoutburst (cf. Boyd et al. (2007)). See Kato et al. (2015a) for more history.

The 2016 superoutburst was detected by M. Moriyama at an unfiltered CCD magnitude of 15.5 on November 17. Observations on a single night yielded three superhumps (table 11). The maximum =2 suffered from large atmospheric extinction and the quality of this measurement was poor. The is omitted from table 3 since there were observations with much more accurate values in the past.

max error
0 57722.2200 0.0011 0. 0015 68
1 57722.2925 0.0021 0. 0030 76
2 57722.3739 0.0022 0. 0015 65
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 11: Superhump maxima of V337 Cyg (2016)

3.11 V1113 Cygni

V1113 Cyg was discovered as a dwarf nova by Hoffmeister (1966). The SU UMa-type nature was identified by Kato et al. (1996b). See Kato et al. (2016a) for more history.

The 2016 superoutburst was detected by H. Maehara at a visual magnitude of 14.3 on July 27 (vsnet-alert 20003). A visual observation by P. Dubovsky on the same night and ASAS-SN detection on the next night indicated further brightening (vsnet-alert 20011, 20015). Thanks to the early detection and notification, growing superhumps were detected (vsnet-alert 20022). The times of superhump maxima are listed in table 12, which clearly indicate the presence of stage A superhumps (figure 12). It may be noteworthy that stage A lasted nearly 40 cycles (figure 12), which may be analogous to long- SU UMa-type dwarf novae with slowly evolving superhumps (such as V1006 Cyg: Kato et al. (2016b); V452 Cas: Kato et al. (2016a)). Since stage A superhumps were observed, a spectroscopic radial-velocity study is desired to determine using the stage A superhump method.

\FigureFile

(85mm,70mm)v1113cygcomp3.eps

Figure 12: Comparison of diagrams of V1113 Cyg between different superoutbursts. A period of 0.07911 d was used to draw this figure. Approximate cycle counts () after the peak of the superoutburst were used. Since the start of the 2016 superoutburst was very well defined, we used the peak of the superoutburst and redefined the cycle counts. The other outbursts were shifted to best match the 2016 one.
max error
0 57599.0116 0.0013 0. 0162 63
1 57599.0971 0.0005 0. 0099 64
2 57599.1790 0.0003 0. 0071 201
3 57599.2586 0.0004 0. 0066 148
14 57600.1407 0.0002 0. 0053 238
15 57600.2193 0.0003 0. 0048 158
52 57603.1492 0.0003 0. 0078 144
53 57603.2275 0.0006 0. 0070 157
54 57603.3179 0.0019 0. 0183 55
65 57604.1787 0.0006 0. 0089 158
66 57604.2578 0.0006 0. 0089 157
89 57606.0721 0.0006 0. 0037 87
90 57606.1513 0.0005 0. 0039 96
91 57606.2324 0.0011 0. 0059 92
103 57607.1743 0.0008 0. 0016 452
104 57607.2518 0.0013 0. 0031 104
114 57608.0431 0.0006 0. 0030 96
115 57608.1199 0.0007 0. 0052 92
116 57608.1991 0.0005 0. 0052 97
117 57608.2779 0.0016 0. 0054 60
141 57610.1706 0.0017 0. 0113 98
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 12: Superhump maxima of V1113 Cyg (2016)

3.12 IX Draconis

IX Dra is one of ER UMa-type dwarf novae (Ishioka et al., 2001). See Kato et al. (2014a) and Olech et al. (2004) for the history.

The 2016 May superoutburst was detected by P. Dubovsky at a visual magnitude of 15.2 on May 29. Subsequent observations detected superhumps (vsnet-alert 19868). The times of superhump maxima are listed in table 13. A combined diagram (figure 13) did not show a strong sign of a stage transition.

In order to determine the change in the supercycle (cf. Otulakowska-Hypka et al. (2013)), we have extracted nine maxima of superoutbursts since 2015 April, when the ASAS-SN team started a good coverage of this field. The mean supercycle between JD 2457142 and 2457305 (2015 April to October) was 54.4(3) d, while it increased to 58.9(3) d between JD 2457420 and 2457657 (2016 February to September). These values are much shorter than what is predicted (should be longer than 62 d by 2015) by a claimed secular trend in Otulakowska-Hypka et al. (2013). The rapid variation suggests that snapshot values as in Otulakowska-Hypka et al. (2013) probably did not reflect the long-term trend well.

\FigureFile

(85mm,70mm)ixdracomp2.eps

Figure 13: Comparison of diagrams of IX Dra between different superoutbursts. A period of 0.06700 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57540.7847 0.0005 0. 0004 56
1 57540.8523 0.0008 0. 0003 62
2 57540.9224 0.0021 0. 0035 26
22 57542.2582 0.0012 0. 0014 95
30 57542.7938 0.0006 0. 0018 71
34 57543.0643 0.0013 0. 0048 123
35 57543.1217 0.0024 0. 0047 123
37 57543.2507 0.0054 0. 0095 117
90 57546.8062 0.0020 0. 0006 64
92 57546.9417 0.0020 0. 0022 58
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 13: Superhump maxima of IX Dra (2016)

3.13 IR Geminorum

IR Gem was discovered as a U Gem-type variable star (AN S5423) by Popowa (1961). Although little was known other than outbursts with an interval of 75 d and amplitudes of 2.5 mag (Popova (1960); Meinunger (1976)),121212 There is a close companion star and old literature often referred to combined magnitudes. this object has been well monitored by AAVSO observers since its discovery. Several outbursts were already recorded in the 1960s (Mayall, 1968). Bond (1978) obtained a spectrum typical for an outbursting dwarf nova. Burenkov and Voikhanskaia (1979) reported a dwarf nova-type spectrum in quiescence. Shafter et al. (1984) identified this object to be an SU UMa-type dwarf nova by detecting superhumps. Shafter et al. (1984) suggested a small mass ratio (either a massive white dwarf or an undermassive secondary) based on a radial-velocity study. Although Feinswog et al. (1988), Lázaro et al. (1990) and Lazaro et al. (1991) reported more detailed spectroscopic studies, the orbital period was not well measured. Observations of superhumps during the 1991 superoutburst were reported in Kato (2001). Kato et al. (2009) reanalyzed this superoutburst and reported another one in 2009. Another superoutburst in 2010 was reported in Kato et al. (2010).

The 2016 superoutburst was detected by the ASAS-SN team at =12.95 on March 22 and =12.00 on March 24. Subsequent observations detected superhumps (vsnet-alert 19645). The times of superhump maxima are listed in table 14. The observation started two days later than the announcement and stage A superhumps were not recorded.

The 2017 superoutburst was detected by K. Kasai on March 12 (vsnet-alert 20763) while observing KaiV36, an ellipsoidal variable star in the field of IR Gem. The outburst was detected early enough and stage A superhumps were observed (figure 14). The object was still in quiescence on March 10. The times of superhump maxima are listed in table 15. The observations were not long enough and was not determined. The for stage A superhumps is 0.068(11), whose errors mainly comes from the uncertainty in the orbital period [0.0684(6) d] (Feinswog et al., 1988). This corresponds to =0.22(4). Accurate determination of the orbital period is desired since the object is bright enough and its behavior during superoutbursts has been well documented.

\FigureFile

(85mm,70mm)irgemcomp.eps

Figure 14: Comparison of diagrams of IR Gem between different superoutbursts. A period of 0.07109 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used. The 2010 superoutburst was preceded by a separate precursor. We shifted the values to best fit the 2016 ones. The result suggests that superhumps started to evolve 20 cycles after the peak of the precursor outburst. The final points in the 2009 superoutbursts probably correspond to traditional late superhumps.
max error
0 57474.0108 0.0006 0. 0046 79
1 57474.0837 0.0007 0. 0026 78
2 57474.1509 0.0014 0. 0062 57
4 57474.2971 0.0003 0. 0017 176
5 57474.3681 0.0003 0. 0015 192
6 57474.4399 0.0003 0. 0006 164
14 57475.0065 0.0012 0. 0007 50
15 57475.0751 0.0014 0. 0029 33
18 57475.2914 0.0003 0. 0009 142
19 57475.3633 0.0003 0. 0020 176
20 57475.4332 0.0004 0. 0010 145
27 57475.9366 0.0014 0. 0085 35
28 57476.0000 0.0007 0. 0011 53
29 57476.0737 0.0011 0. 0039 52
32 57476.2860 0.0005 0. 0037 60
33 57476.3554 0.0005 0. 0023 42
56 57477.9826 0.0009 0. 0002 101
57 57478.0542 0.0010 0. 0009 89
60 57478.2696 0.0014 0. 0038 34
61 57478.3376 0.0004 0. 0010 63
74 57479.2585 0.0004 0. 0010 103
75 57479.3282 0.0004 0. 0002 127
76 57479.3991 0.0004 0. 0001 152
104 57481.3736 0.0007 0. 0091 67
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 14: Superhump maxima of IR Gem (2016)
max error
0 57825.4884 0.0014 0. 0181 72
11 57826.2930 0.0001 0. 0015 314
12 57826.3662 0.0002 0. 0033 78
13 57826.4373 0.0003 0. 0031 78
14 57826.5087 0.0005 0. 0031 60
25 57827.2952 0.0001 0. 0045 232
26 57827.3666 0.0002 0. 0045 218
27 57827.4378 0.0002 0. 0044 116
28 57827.5083 0.0004 0. 0035 68
39 57828.2898 0.0005 0. 0000 78
40 57828.3617 0.0009 0. 0005 56
41 57828.4340 0.0004 0. 0014 78
42 57828.5057 0.0005 0. 0017 67
53 57829.2867 0.0003 0. 0022 65
54 57829.3563 0.0004 0. 0040 78
55 57829.4277 0.0005 0. 0040 79
56 57829.4998 0.0005 0. 0033 72
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 15: Superhump maxima of IR Gem (2017)

3.14 NY Herculis

NY Her was originally discovered by Hoffmeister (1949) as a Mira-type variable. Based on photographic observations by Pastukhova (1988) and the CRTS detection on 2011 June 10, the object was identified as an SU UMa-type dwarf nova with a short supercycle (Kato et al., 2013). For more history, see Kato et al. (2013).

The 2016 June superoutburst was detected by the ASAS-SN team at =16.19 on June 28. Subsequent observations detected superhumps (vsnet-alert 19938, 19939, 19948). The times of superhump maxima are listed in table 16. There was a rather smooth transition from stage B to C. Since the 2016 observations was much better than the 2011 one, we provide an updated superhump profile in figure 15. It is noteworthy that the mean superhump amplitude (0.10 mag) is much smaller than most of SU UMa-type dwarf novae with similar (or ) (see figure 16). Such an unusual low superhump amplitude is commonly seen in period bouncers and it may be a signature that NY Her is in a different evolutionary location from the standard one with this .

ASAS-SN light curve suggest that bright outbursts (likely superoutbursts) tend to occur in every 60–70 d (figure 17). We selected long outbursts (presumable superoutbursts) from the ASAS-SN and Poyner’s observations and listed in table 17. Note that we selected the brightest points of outbursts and they do not necessarily reflect the starts of the outbursts. These maxima can be well expressed by a period of 63.5(2) d with residuals less than 5 d. We consider that this period is the supercycle of this system. The entire durations of superoutbursts were less than 10 d, which are much shorter than those in ER UMa-type dwarf nova (cf. Kato and Kunjaya (1995); Robertson et al. (1995)) but are similar to that of V503 Cyg with a supercycle of 89 d (Harvey et al., 1995). Although the supercycle is between ER UMa-type dwarf novae and ordinary SU UMa-type dwarf novae, it is not clear whether NY Her fills a gap between them since NY Her does not have intermediate properties between them. NY Her may be classified as an unique object with a short supercycle and a small superhump amplitude despite the relatively long .

\FigureFile

(85mm,110mm)nyher2016shpdm.eps

Figure 15: Superhumps in NY Her during the superoutburst plateau (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
\FigureFile

(88mm,70mm)humpampporb2.eps

Figure 16: Dependence of superhump amplitudes on orbital period. The superoutburst samples are described in subsection 4.7.1 in Kato et al. (2012a). We selected the range of respect to the peak superhump amplitude to illustrate the maximum superhump amplitudes. The curve indicates a spline-smoothed interpolation of the sample in Kato et al. (2012a). The location of NY Her (reflecting the first night of observation; we consider that these observations were early enough to make a comparison in this figure) is shown by stars. The single point right to NY Her is a superhump of QY Per in 1999. The other superhumps of the same superoutburst had amplitudes larger than 0.2 mag and this measurement does not reflect the characteristic amplitude of superhumps in QY Per.
\FigureFile

(88mm,70mm)nyherasas.eps

Figure 17: ASAS-SN and unfiltered CCD light curve of NY Her. Filled circles and squares represent ASAS-SN and Poyner’s measurements, respectively. Although details of each outburst are not very clear, bright outbursts (likely superoutbursts) tend to occur in every 60–70 d. The maxima of bright outbursts listed in table 17 and covered by observations in this figure are shown by ticks.
max error
0 57568.7208 0.0015 0. 0081 85
1 57568.8020 0.0010 0. 0026 141
2 57568.8771 0.0009 0. 0032 106
3 57568.9548 0.0039 0. 0011 40
9 57569.4083 0.0010 0. 0016 39
10 57569.4829 0.0009 0. 0026 33
13 57569.7107 0.0050 0. 0018 38
14 57569.7885 0.0017 0. 0004 74
15 57569.8671 0.0028 0. 0033 75
16 57569.9368 0.0015 0. 0027 67
27 57570.7743 0.0011 0. 0025 74
29 57570.9240 0.0023 0. 0010 75
36 57571.4560 0.0013 0. 0033 54
37 57571.5267 0.0015 0. 0017 52
40 57571.7561 0.0013 0. 0007 73
41 57571.8337 0.0014 0. 0027 66
42 57571.9149 0.0016 0. 0082 74
49 57572.4354 0.0010 0. 0009 38
50 57572.5121 0.0012 0. 0001 36
53 57572.7474 0.0027 0. 0084 72
54 57572.8150 0.0018 0. 0004 66
55 57572.8892 0.0017 0. 0011 74
56 57572.9733 0.0048 0. 0074 29
58 57573.1254 0.0084 0. 0081 73
59 57573.1964 0.0032 0. 0035 74
63 57573.4910 0.0012 0. 0046 103
64 57573.5729 0.0019 0. 0016 48
66 57573.7205 0.0019 0. 0020 56
67 57573.8032 0.0024 0. 0050 66
68 57573.8722 0.0015 0. 0017 72
69 57573.9475 0.0030 0. 0020 50
75 57574.3993 0.0028 0. 0042 19
76 57574.4757 0.0012 0. 0035 38
80 57574.7808 0.0012 0. 0010 68
81 57574.8619 0.0014 0. 0044 74
82 57574.9277 0.0016 0. 0054 52
106 57576.7464 0.0051 0. 0026 24
114 57577.3474 0.0036 0. 0069 30
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 16: Superhump maxima of NY Her (2016)
Cycle JD2400000 magnitude
0 56744 16.12
1 56808 15.94
2 56872 16.08
5 57062 15.74
6 57126 15.78
7 57195 16.15
8 57258 15.94
11 57447 15.74
12 57505 15.96
13 57568 16.19
Table 17: List of recent superoutbursts of NY Her

3.15 MN Lacertae

This object (=VV 381) was discovered by Miller (1971). Relatively frequent outbursts were recorded in Miller (1971) and the object was originally considered to be a Z Cam-type dwarf nova. T. Kato, however, noted a very faint quiescence during a systematic survey of -band photometry of dwarf novae (1990, unpublished) and he suggested that the outburst amplitude should be comparable to those of SU UMa-type dwarf novae.

Since this object was initially cataloged as a Z Cam-type dwarf nova, Simonsen (2011) included it as a target for “Z CamPaign” project. As a result, the outburst behavior was relatively well recorded in the AAVSO database, particularly in 2010–2012. The possibility of an SU UMa-type dwarf nova was particularly noted after a long outburst in 2011 June (vsnet-alert 13420, 13424). During this outburst, accurate astrometry was obtained confirming that the true quiescent magnitude is indeed faint (22nd mag or even fainter). There was another outburst in 2012 October, during which a call for observations of superhumps was issued (vsnet-alert 15063). Following this outburst, the object was withdrawn from the Z CamPaign project and it has not been observed as frequently as before.

The 2016 bright outburst was detected by the ASAS-SN team at =15.32 on October 30. Single-night observations on October 31 indeed detected superhumps (vsnet-alert 20283; figure 18). The times of superhump maxima were BJD 2457693.2873(15) (=37) and 2457693.3684(8) (=53). The best superhump period by the PDM method is 0.080(1) d. Although the SU UMa-type nature was confirmed, more observations are needed to establish a more accurate superhump period.

Thanks to the excellent coverage in 2010–2012, we could determine the supercycle. The maxima of superoutbursts (table 18) can be expressed by a supercycle of 180(8) d with the maximum of 14 d. The result is consistent with the high outburst frequency reported in Miller (1971).

\FigureFile

(85mm,110mm)mnlacshlc.eps

Figure 18: Superhumps in MN Lac (2016).
Year Month Day max -mag
2010 11 6 55506 15.93
2011 5 31 55713 15.74
2011 11 24 55890 16.12
2012 4 30 56048 15.94
JD2400000.
Table 18: List of likely superoutbursts of MN Lac in 2010–2012

3.16 V699 Ophiuchi

This object was discovered as a dwarf nova (HV 10577) with a photographic range of 13.8 to fainter than 16.0 (Boyce, 1942). Boyce (1942) recorded five outbursts between 1937 June 5 and 1940 July 5. The intervals of the first four outbursts were in the range of 320–390 d. Although Walker and Olmsted (1958) presented a finding chart, later spectroscopic studies have shown that the marked object is a normal star (Zwitter and Munari (1996); Liu et al. (1999)).

On 1999 April 16, A. Pearce detected an outburst (vsnet-alert 2877). Accurate astrometry and photometry of the outbursting object indicated that the true V699 Oph is an unresolved companion to a 16-th magnitude star (vsnet-alert 2878, vsnet-chat 1810, 1868). The first confirmed superoutburst was recorded in 2003. This outburst was preceded by a separate precursor and followed by a rebrightening, forming a “triple outburst”. (Kato et al., 2009). The 2008 and 2010 superoutbursts were also reported in Kato et al. (2009) and Kato et al. (2010), respectively.

The 2016 superoutburst was detected by the ASAS-SN team at =14.56 on May 15 and by R. Stubbings at a visual magnitude of 14.4 on the same night. Time-resolved photometric observations were obtained on two nights and the times of superhump maxima are listed in table 19. The 2016 observation probably recorded the early part of stage B superhumps (figure 19).

\FigureFile

(88mm,70mm)v699ophcomp2.eps

Figure 19: Comparison of diagrams of V699 Oph between different superoutbursts. A period of 0.07031 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57527.1699 0.0013 0. 0015 122
1 57527.2371 0.0013 0. 0015 128
28 57529.1344 0.0016 0. 0001 77
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 19: Superhump maxima of V699 Oph (2016)

3.17 V344 Pavonis

This dwarf nova was discovered in outburst on 1990 July 21. The object was spectroscopically confirmed as a dwarf nova. There were two outbursts recorded in archival plates between 1979 May and 1984 September (Maza et al., 1990). Mason and Howell (2003) obtained a typical spectrum of a dwarf nova in quiescence. Uemura et al. (2004) studied the 2004 outburst and identified the SU UMa-type nature. The analysis was refined in Kato et al. (2009).

The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 14.4 on April 25. Subsequent observations detected superhumps (vsnet-alert 19796). The times of superhump maxima are listed in table 20. Time-resolved photometry was obtained only in the later phase of the superoutbursts both in 2004 and 2016. The superhump stage has been therefore unclear (figure 20). We listed a global in table 3. Observations in the earlier phase of the superoutburst are needed to characterize superhumps of this object better.

\FigureFile

(88mm,70mm)v344pavcomp.eps

Figure 20: Comparison of diagrams of V344 Pav between different superoutbursts. A period of 0.07988 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used. Since the start of the 2004 outburst was not well constrained, we shifted the diagram so that the rapid fading of the two superoutbursts match each other.
max error
0 57507.7957 0.0006 0. 0020 20
1 57507.8734 0.0007 0. 0043 22
13 57508.8391 0.0018 0. 0030 22
14 57508.9148 0.0031 0. 0013 6
25 57509.7979 0.0011 0. 0032 23
26 57509.8726 0.0016 0. 0019 21
38 57510.8369 0.0010 0. 0037 22
39 57510.9169 0.0050 0. 0039 8
50 57511.7928 0.0010 0. 0012 22
51 57511.8699 0.0024 0. 0016 21
63 57512.8322 0.0018 0. 0022 23
64 57512.9096 0.0031 0. 0003 10
75 57513.7862 0.0033 0. 0024 20
76 57513.8651 0.0022 0. 0034 21
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 20: Superhump maxima of V344 Pav (2016)

3.18 V368 Pegasi

V368 Peg is a dwarf nova (Antipin Var 63) discovered by Antipin (1999). See Kato et al. (2016a) for the summary of the history. The 2016 superoutburst was detected by P. Schmeer at a visual magnitude of 13.0 on September 28. Time-resolved photometry was performed only on a single night. The resultant superhump maxima were BJD 2457661.4175(5) (=66) and 2457661.4883(4) (=76).

3.19 V893 Sco

V893 Sco was discovered as a variable star by Satyvoldiev (1972). The variable had been lost for a long time, and was rediscovered by K. Haseda (Kato et al., 1998). For more historical information, see Kato et al. (2014a). This object is an eclipsing SU UMa-type dwarf nova (cf. Bruch et al. (2000); Matsumoto et al. (2000).

The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 12.8 on March 21. It once faded to =13.64 on the same night and brightened to =12.37 on March 25 (vsnet-alert 19652). The outburst on March 21 should have been a precursor. Our time-resolved photometry started on March 28 and detected superhumps (vsnet-alert 19661; figure 21). Since our observation started relatively late, we could record only the final part of the superoutburst. Later observations were dominated by the orbital humps and we could only extract a small number of superhump maxima outside the eclipses (table 21). We obtained the eclipse ephemeris for the use of defining the orbital phases in this paper

(3)

using the MCMC modeling (Kato et al., 2013) using the data up to Kato et al. (2014a) and current set of observation.

\FigureFile

(85mm,110mm)v893scoshlc.eps

Figure 21: Eclipses and superhumps in V893 Sco (2016). The data were binned to 0.002 d.
max error phase
0 57476.1964 0.0017 0. 0062 0.10 92
1 57476.2774 0.0007 0. 0002 0.05 118
2 57476.3528 0.0007 0. 0009 0.06 117
13 57477.1799 0.0011 0. 0067 0.09 115
14 57477.2601 0.0049 0. 0122 0.11 111
15 57477.3120 0.0015 0. 0105 0.07 112
16 57477.3987 0.0016 0. 0015 0.11 69
26 57478.1390 0.0013 0. 0049 0.17 42
BJD2400000.
Against max .
Orbital phase.
Number of points used to determine the maximum.
Table 21: Superhump maxima of V893 Sco (2016)

3.20 V493 Serpentis

This object (=SDSS J155644.24000950.2) was selected as a dwarf nova by SDSS (Szkody et al., 2002). The SU UMa-type nature was identified by observations of the 2006 and 2007 superoutbursts (Kato et al., 2009). See Kato et al. (2014b) for more history.

The 2016 superoutburst was detected by T. Horie at a visual magnitude of 12.5 on June 5. It was pointed out by H. Maehara the outburst already started on June 1 (vsnet-alert 19872). Time-resolved photometry was carried out on two nights, yielding superhump maxima in table 22. A comparison of diagrams (figure 22) suggest that these observations recorded the early phase of stage C.

\FigureFile

(88mm,70mm)v493sercomp3.eps

Figure 22: Comparison of diagrams of V493 Ser between different superoutbursts. A period of 0.08310 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57547.3780 0.0013 0. 0006 26
1 57547.4618 0.0008 0. 0005 25
12 57548.3728 0.0012 0. 0015 22
13 57548.4526 0.0008 0. 0014 25
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 22: Superhump maxima of V493 Ser (2016)

3.21 AW Sagittae

AW Sge was discovered as a dwarf nova by Wolf and Wolf (1906). The object was identified as an SU UMa-type dwarf nova during the 2000 outburst (Kato et al., 2009). See Kato et al. (2014a) for more history.

The 2016 superoutburst was detected by R. Stubbings at a visual magnitude of 14.6 on June 14. Time-resolved photometric observations were carried out on a single night and yielded the superhumps maxima: BJD 2457558.3859(5) (=75) and 2457558.4606(9) (=50).

3.22 V1389 Tauri

This object was discovered by K. Itagaki at an unfiltered CCD magnitude of 14.1 on 2008 August 7 (Yamaoka et al., 2008). There was an X-ray counterpart (1RXS J040700.2005247) and the dwarf nova-type classification was readily suggested. The object was recorded already in outburst at =13.5 on August 4 in the ASAS-3 (Pojmański, 2002) data (vsnet-alert 10419). There were two past outbursts (2004 October 20 and 2006 March 16) recorded in the ASAS-3 data (vsnet-alert 10419). Subsequent observations detected superhumps (vsnet-alert 10422, 10423). This outburst was studied in Kato et al. (2009). Another superoutburst in 2010 was studied in Kato et al. (2010).

The 2016 superoutburst was detected by the ASAS-SN team at =13.52 on October 23. Subsequent observations detected superhumps (vsnet-alert 20267). The times of superhump maxima are listed in table 23. As in other typical long- systems (cf. figure 4 in Kato et al. (2009)), stage B was relatively short. A comparison of the diagrams has confirmed that the superhumps recorded in 2008 were indeed stage C ones (figure 23). Although individual superhump maxima were not measured, a PDM analysis of the post-superoutburst data (4.5 d segment after BJD 2457697) detected a period of 0.08000(11) d. This value suggests that stage C superhump lasted even after the termination of the superoutburst.

\FigureFile

(88mm,70mm)v1389taucomp.eps

Figure 23: Comparison of diagrams of V1389 Tau between different superoutbursts. A period of 0.08046 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used. Since the start of the 2010 superoutburst was not known, we have shifted the diagram to best fit the others.
max error
0 57686.0276 0.0036 0. 0098 97
1 57686.1152 0.0006 0. 0023 176
2 57686.1979 0.0004 0. 0002 178
3 57686.2735 0.0008 0. 0044 104
9 57686.7562 0.0009 0. 0025 25
10 57686.8328 0.0021 0. 0061 21
21 57687.7177 0.0013 0. 0029 17
22 57687.8021 0.0010 0. 0014 21
34 57688.7695 0.0009 0. 0069 23
35 57688.8484 0.0006 0. 0058 17
46 57689.7291 0.0010 0. 0048 15
47 57689.8109 0.0008 0. 0064 16
52 57690.2159 0.0009 0. 0107 98
59 57690.7712 0.0015 0. 0050 20
60 57690.8497 0.0007 0. 0033 16
71 57691.7314 0.0029 0. 0033 22
72 57691.8082 0.0020 0. 0000 20
85 57692.8488 0.0018 0. 0014 16
96 57693.7318 0.0016 0. 0000 22
97 57693.8085 0.0016 0. 0034 20
109 57694.7704 0.0021 0. 0034 20
110 57694.8447 0.0015 0. 0093 16
121 57695.7334 0.0045 0. 0022 22
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 23: Superhump maxima of V1389 Tau (2016)

3.23 SU Ursae Majoris

This object is the prototype of SU UMa-type dwarf novae. See Kato et al. (2015a) for the history. The 2017 superoutburst was detected by E. Muyllaert at a visual magnitude of 11.3 on February 23. Only single superhump at BJD 2457810.5647(3) (=89) was observed.

3.24 HV Virginis

HV Vir was originally discovered by Schneller (1931) in outburst on 1929 February 11. The object was also given a designation of NSV 6201 as a suspected variable. Duerbeck (1984) and Duerbeck (1987) classified it as a classical nova and provided a light curve of the 1929 outburst based on his examination of archival plates. Amateur observers, particularly by the Variable Star Observers’ League in Japan (VSOLJ), suspected it to be a dwarf nova and started monitoring since 1987 [i.e. following the publication of Duerbeck (1987)]. The object was caught in outburst by P. Schmeer on 1992 April 20 at a visual magnitude of 12.0 (Schmeer et al., 1992). The 1992 outburst was extensively studied (Barwig et al. (1992); Leibowitz et al. (1994); Kato et al. (2001)). It might be worth noting that Barwig et al. (1992) recorded low-amplitude variations with a period corresponding to the orbital period, their interpretation (originating from the hot spot as in quiescence) was strongly affected by Patterson et al. (1981). Although Szkody et al. (1992) reported the detection of superhumps, the detailed result has not been published. Leibowitz et al. (1994) reported the detection of historical outbursts in 1939, 1970 and 1981 in archival plates. Although Leibowitz et al. (1994) noted chaotic “early superhump variability”, its period was not precisely determined. Leibowitz et al. (1994) recorded superhumps and reported a negative , which was incorrect due to an error in cycle counts probably misguided by the received wisdom at that time that SU UMa-type dwarf novae universally show negative (cf. Warner (1985); Patterson et al. (1993)). Using additional observations and all available data, Kato et al. (2001) clarified that this object showed two types of superhumps (early superhumps and ordinary superhumps) and the for ordinary superhumps was positive. Kato et al. (2001) proposed the close similarity to AL Com (cf. Kato et al. (1996a)) and WZ Sge, giving a basis of the modern concept of WZ Sge-type dwarf novae (Kato, 2015).

The object underwent another superoutburst in 2002. This outburst was also extensively studied by Ishioka et al. (2003), who established the positive using a much more complete set of observations than in 1992. Patterson et al. (2003) also reported the superhump period of the same outburst and the orbital period of 0.057069(6) d from quiescent photometry. There was another superoutburst in 2008, which was reported in Kato et al. (2009).

The 2016 superoutburst was detected by the ASAS-SN team at =12.0 on March 10 (cf. vsnet-alert 19571). Initial observations already detected early superhumps (vsnet-alert 19573, 19576, 19589; figure 25). The object then developed ordinary superhumps (vsnet-alert 19581, 19599, 19633). The times of superhump maxima are listed in table 24. The data very clearly demonstrate the presence of stages A and B, although there was an observational gap in the middle of stage B. The superhump period of stage A was very ideally determined to be 0.05907(6) d (cf. figure 24). This period gives the fractional superhump excess of =0.034(1), which corresponds to =0.093(3). This value supersedes the earlier determination by the same method to be =0.072(1) using the less extensive 2002 data. The period was determined for the 2002 data from single-night observations assuming that stage A continued up to the first observation of stage B while the present observation obtained an almost complete coverage of stage A (see figure 24). It was likely that the error was underestimated in the 2002 superoutburst. The outburst started rapid fading on March 29–30 and the entire duration of the superoutburst was at least 20 d. Despite dense observations, no post-outburst rebrightening was recorded.

A PDM analysis of the post-superoutburst observations yielded a period of 0.05799(2) d (figure 26). This period corresponds to a disk radius of 0.33 assuming that the precession rate is not affected by the pressure effect. The value is in the range of 0.30–0.38 determined for well-observed WZ Sge-type dwarf novae (Kato and Osaki, 2013).

The period of early superhumps [0.057000(8) d] is in agreement with 0.056996(9) d determined from the 2008 observation (from the observations reported in Kato et al. (2009)). The quality of past observations were lower: 0.057085 d (without error estimate) for the 1992 outburst (Kato et al., 2001), which was based only on published times of maxima, and 0.0569(1) d for the 2002 outburst (Ishioka et al., 2003). The current observations, combined with the 2008 data, established the period of early superhumps of this object to a precision directly comparable to the orbital period for the first time. The 2016 and 2008 periods were 0.13(2)% and 0.13(3)% shorter than the orbital period, respectively.

\FigureFile

(85mm,70mm)hvvircomp2.eps

Figure 24: Comparison of diagrams of HV Vir between different superoutbursts. A period of 0.05828 d was used to draw this figure. Approximate cycle counts () after the emergence of ordinary superhumps were used. After the high-quality observations in 2016, it became apparent that the emergence of ordinary superhumps was not well recorded in the past superoutbursts. The cycle counts were shifted by 20, 10 and 15 for the 1992, 2002 and 2008 superoutbursts, respectively, to match the 2016 observations.
\FigureFile

(85mm,110mm)hvvir2016eshpdm.eps

Figure 25: Early superhumps in HV Vir (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
\FigureFile

(85mm,110mm)hvvir2016postpdm.eps

Figure 26: Post-superoutburst superhumps in HV Vir (2016). (Upper): PDM analysis. The data for BJD 2457478–2457494 were used. (Lower): Phase-averaged profile.
max error max error
0 57463.6347 0.0024 0. 0131 24 52 57466.6775 0.0004 0. 0006 28
1 57463.6999 0.0018 0. 0061 29 53 57466.7342 0.0005 0. 0009 23
2 57463.7567 0.0018 0. 0076 24 54 57466.7940 0.0005 0. 0006 19
3 57463.8193 0.0012 0. 0033 20 55 57466.8508 0.0004 0. 0008 21
4 57463.8719 0.0011 0. 0089 23 64 57467.3739 0.0002 0. 0020 108
7 57464.0516 0.0006 0. 0039 52 65 57467.4315 0.0003 0. 0027 118
8 57464.1091 0.0005 0. 0047 48 66 57467.4897 0.0003 0. 0027 152
9 57464.1684 0.0008 0. 0036 33 67 57467.5481 0.0004 0. 0025 59
10 57464.2286 0.0005 0. 0017 58 68 57467.6058 0.0010 0. 0031 48
11 57464.2889 0.0005 0. 0004 60 69 57467.6638 0.0005 0. 0033 73
12 57464.3473 0.0003 0. 0005 47 70 57467.7221 0.0010 0. 0033 23
14 57464.4656 0.0003 0. 0023 137 71 57467.7828 0.0023 0. 0009 14
15 57464.5247 0.0002 0. 0032 172 84 57468.5436 0.0017 0. 0027 41
16 57464.5826 0.0002 0. 0028 172 85 57468.5948 0.0006 0. 0044 65
17 57464.6416 0.0002 0. 0036 150 86 57468.6539 0.0008 0. 0035 27
18 57464.7017 0.0003 0. 0054 40 87 57468.7117 0.0009 0. 0040 24
19 57464.7606 0.0004 0. 0060 32 88 57468.7705 0.0011 0. 0035 20
20 57464.8198 0.0005 0. 0070 19 89 57468.8289 0.0040 0. 0033 20
21 57464.8783 0.0005 0. 0072 25 90 57468.8858 0.0005 0. 0046 26
25 57465.1110 0.0006 0. 0070 50 95 57469.1772 0.0015 0. 0045 30
31 57465.4597 0.0002 0. 0061 166 103 57469.6438 0.0023 0. 0040 28
32 57465.5176 0.0003 0. 0058 81 104 57469.7045 0.0008 0. 0015 25
33 57465.5758 0.0003 0. 0057 119 105 57469.7619 0.0008 0. 0024 21
34 57465.6346 0.0002 0. 0063 134 107 57469.8809 0.0017 0. 0001 26
35 57465.6924 0.0004 0. 0058 46 190 57474.7202 0.0009 0. 0045 25
36 57465.7508 0.0003 0. 0060 38 221 57476.5205 0.0007 0. 0010 52
37 57465.8097 0.0007 0. 0066 15 222 57476.5756 0.0009 0. 0041 50
38 57465.8655 0.0007 0. 0042 23 224 57476.6946 0.0024 0. 0017 14
48 57466.4469 0.0005 0. 0030 56 225 57476.7576 0.0040 0. 0031 15
49 57466.5038 0.0004 0. 0017 57 226 57476.8197 0.0008 0. 0069 33
50 57466.5609 0.0004 0. 0005 58 227 57476.8722 0.0026 0. 0012 39
51 57466.6193 0.0003 0. 0007 79
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 24: Superhump maxima of HV Vir (2016)

3.25 Nsv 2026

This object was discovered as a variable star (=HV 6907) by Hoffleit (1935). The SU UMa-type nature was confirmed during the 2015 superoutburst. For more history, see Kato et al. (2016a).

There was a superoutburst in 2016 February (Kato et al., 2016a). Another superoutburst occurred in 2016 November, which was detected by J. Shears at an unfiltered CCD magnitude of 14.19 and by E. Muyllaert at a visual magnitude of 14.0 on November 25. The object was further observed to brighten to a visual magnitude of 13.2 on November 26. The times of superhump maxima are listed in table 25. These superhumps were likely stage B ones (figure 27). As judged from the interval of two superoutbursts in 2016 and the supercycle of 95 d (Kato et al., 2016a), two superoutbursts were likely missed between the two superoutbursts in 2016.

\FigureFile

(85mm,70mm)nsv2026comp2.eps

Figure 27: Comparison of diagrams of NSV 2026 between different superoutbursts. A period of 0.06982 d was used to draw this figure. Approximate cycle counts () after the starts of the outbursts were used. The start of the 2016 outburst refers to the precursor outburst. Since the start of the 2015 outburst was not well constrained, the curve was shifted as in the 2016 one.
max error
0 57722.4877 0.0005 0. 0002 78
1 57722.5579 0.0006 0. 0002 64
13 57723.3966 0.0005 0. 0000 59
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 25: Superhump maxima of NSV 2026 (2016b)

3.26 Nsv 14681

NSV 14681 was discovered as a variable star (SVS 749) of unknown type with a photographic range of 14 to fainter than 14.5 (Belyavskii, 1936). The CRTS team detected an outburst at an unfiltered CCD magnitude of 15.6 on 2007 June 13 and it was readily identified with NSV 14681 (Drake et al., 2014). The CV is a fainter component of a close pair (Kato et al., 2012b). The CRTS team detected another outburst at 16.4 mag on 2009 September 14.

The 2016 outburst was detected by the ASAS-SN team at =14.35 on October 19. Subsequent observations detected superhumps (vsnet-alert 20245, 20256; figure 28). The times of superhump maxima are listed in table 26. The superhump stage is unknown. The object is on the lower edge of the period gap.

\FigureFile

(85mm,110mm)nsv14681shpdm.eps

Figure 28: Superhumps in NSV 14681 (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
max error
0 57684.5223 0.0004 0. 0002 90
34 57687.5852 0.0005 0. 0005 90
35 57687.6745 0.0013 0. 0002 59
77 57691.4572 0.0010 0. 0001 76
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 26: Superhump maxima of NSV 14681 (2016)

3.27 1rxs j161659.5620014

This object (hereafter 1RXS J161659) was initially identified as an X-ray selected variable (also given a name as MASTER OT J161700.81620024.9), which was first detected in bright state on 2012 September 11 at an unfiltered CCD magnitude of 14.4 (Balanutsa et al., 2013). The dwarf nova-type variability was confirmed by analysis of the CRTS data (Balanutsa et al. (2013); see also vsnet-alert 16079, 16720).

The 2016 April outburst was detected by the ASAS-SN team at =14.74 on April 22. Subsequent observations detected superhumps (vsnet-alert 19763, 19765, 19772; figure 29). The times of superhump maxima are listed in table 27. The nature of the humps for 155 (post-superoutburst) is unclear due to the gap in the observation. These humps may be either traditional late superhumps or the extension of stage C superhumps (if it is the case, the cycle count should be increased by one). We consider the latter possibility less likely, since this interpretation requires the period of stage C superhumps to be 0.07065(2) d, which appears to be too short (by 1%) shorter than that of stage B superhumps. We do not use these maxima in obtaining the periods in table 3.

The 2016 July outburst was detected by the CRTS team at an unfiltered CCD magnitude of 14.63 on July 10 (cf. vsnet-alert 19970). Although it was considered to be too early for a next superoutburst, subsequent observations detected superhumps (vsnet-alert 19996). The times of superhump maxima are listed in table 28. As in the superoutburst in 2016 April, the nature of maxima for 112 (post-superoutburst) was unclear. A comparison of diagrams between two superoutbursts is given in figure 30.

These observations indicate that the supercycle is only 80 d. We studied past ASAS-SN observations and detected outbursts (table 29). The outburst pattern became more regular since the 2015 July (it may have been due to the change in the variability in this system or the improvement of observations in ASAS-SN) and we obtained a mean supercycle of 89(1) d from five most recent superoutbursts (with values less than 8 d). Despite the shortness of the supercycle, normal outbursts are not as frequent as in ER UMa-type dwarf novae (Kato and Kunjaya (1995); Robertson et al. (1995)) or active SU UMa-type dwarf novae, such as SS UMi (Kato et al. (2000); Olech et al. (2006)) and BF Ara (Kato et al., 2001a). The object resembles V503 Cyg with a supercycle of 89 d with a few normal outbursts between superoutbursts (Harvey et al., 1995). V503 Cyg is known to show different states (Kato et al., 2002b), which is now considered to be a result of the disk tilt suppressing normal outbursts (Ohshima et al. (2012); Osaki and Kato (2013a); Osaki and Kato (2013b)). A search for negative superhumps in 1RXS J161659 would be fruitful.

\FigureFile

(85mm,110mm)j1616shpdm.eps

Figure 29: Superhumps in 1RXS J161659 during the superoutburst plateau (2016). (Upper): PDM analysis. (Lower): Phase-averaged profile.
\FigureFile

(88mm,70mm)j1616comp.eps

Figure 30: Comparison of diagrams of 1RXS J161659 between different superoutbursts. A period of 0.07130 d was used to draw this figure. Approximate cycle counts () after the start of the superoutburst were used.
max error
0 57502.3747 0.0003 0. 0019 72
1 57502.4450 0.0004 0. 0008 72
14 57503.3701 0.0020 0. 0019 26
15 57503.4444 0.0004 0. 0010 64
16 57503.5175 0.0007 0. 0028 65
17 57503.5870 0.0007 0. 0008 70
18 57503.6614 0.0016 0. 0039 41
27 57504.3101 0.0016 0. 0102 47
28 57504.3718 0.0005 0. 0006 127
29 57504.4442 0.0005 0. 0016 149
30 57504.5127 0.0009 0. 0013 68
31 57504.5860 0.0007 0. 0007 70
32 57504.6547 0.0006 0. 0021 50
42 57505.3713 0.0019 0. 0009 37
43 57505.4437 0.0006 0. 0019 76
56 57506.3682 0.0009 0. 0015 74
57 57506.4405 0.0004 0. 0005 149
58 57506.5111 0.0004 0. 0013 92
59 57506.5817 0.0005 0. 0021 68
70 57507.3664 0.0016 0. 0025 50
71 57507.4345 0.0005 0. 0058 90
72 57507.5058 0.0005 0. 0059 83
73 57507.5757 0.0005 0. 0073 79
74 57507.6476 0.0013 0. 0068 47
155 57513.4440 0.0016 0. 0084 27
156 57513.5071 0.0021 0. 0001 32
157 57513.5819 0.0012 0. 0035 36
BJD2400000.
Against max .
Number of points used to determine the maximum.
Table 27: Superhump maxima of 1RXS J161659 (2016)
max error