Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV. The Fourth Year (2011–2012)
| Autor: | Kazuyoshi Imamura, Kevin B. Paxson, Peter Starr, Franz-Josef Hambsch, Greg Bolt, Jeremy Shears, Irina Voloshina, Joseph Ulowetz, Richard Sabo, Denis Samsonov, Enrique de Miguel, Javier Ruiz, Shinichi Nakagawa, Pavol A. Dubovsky, Elena P. Pavlenko, Sergey Yu. Shugarov, S. A. Korotkiy, Boris L. Satovski, Etienne Morelle, Arne Henden, Yutaka Maeda, Minako Ogi, Hubert Hautecler, Hiroshi Itoh, Taichi Kato, Michael Linnolt, Colin Littlefield, Fabio Martinelli, Hiroyuki Maehara, Igor Kudzej, Aleksei A. Sosnovskij, Vladimir Gerke, Akihiko Fukui, Youichirou Nakashima, Katsura Matsumoto, Roger D. Pickard, Eddy Muyllaert, Viktor Malanushenko, William Stein, Hiroshi Kobayashi, Oksana I. Antonyuk, Nikolaj V. Pit, Takashi Nomoto, Takuma Nakazato, Paul J. Tristram, Mike Simonsen, Christopher Stockdale, Rod Stubbings, Hideo Nishimura, Kiyoshi Kasai, Koh-ichi Itagaki, Nikolai Parakhin, Berto Monard, Tamás Tordai, Yuya Wakabayashi, Gary Poyner, Ryo Noguchi, Seiichi Yoshida, Shawn Dvorak, Maksim V. Andreev, Chihiro Akasaka, Tomoya Aoki, Ryosuke Takagi, Walter MacDonald Ii, Kirill A. Antonyuk, Rikako Ono, David Boyd, Robert Fidrich, Natalia Katysheva, Drahomir Chochol, Gianluca Masi, Keisuke Taniuchi, Timur V. Kryachko, Aleksei V. Baklanov, Kenji Hirosawa, Ian Miller, Seiichiro Kiyota, William N. Goff, Jochen Pietz, D. Denisenko, Arto Oksanen, Tomohito Ohshima, Thomas Krajci, Hidehiko Akazawa, Kazuyuki Ogura, Atsushi Miyashita, Kenji Tanabe, Andrey V. Samokhvalov |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 2053-051X 0004-6264 |
| DOI: | 10.1093/pasj/65.1.23 |
| Popis: | Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we studied 86 SU UMa-type dwarf novae. We confirmed the general trends such as the relation between period derivatives and orbital periods. There are some systems showing positive period derivatives despite the long orbital periods. We observed the 2011 outburst of the WZ Sge-type dwarf nova BW Scl, and recorded an O-C diagram similar to those of previously known WZ Sge-type dwarf novae. The WZ Sge-type dwarf nova OT J184228.1+483742 showed an unusual pattern of double outbursts composed of an outburst with early superhumps and one with ordinary superhumps. We propose an interpretation that a very small growth rate of the 3:1 resonance due to an extremely low mass-ratio led to a quenching of the superoutburst before the ordinary superhumps appeared. We studied ER UMa-type dwarf novae and found that V1159 Ori showed positive superhumps similar to ER UMa in the 1990s. The recently recognized ER UMa-type object BK Lyn dominantly showed negative superhumps, and its behavior was very similar to the present-day state of ER UMa. The pattern of period variations in AM CVn-type objects were very similar to short-period hydrogen-rich SU UMa-type dwarf novae, making them helium analogue of hydrogen-rich SU UMa-type dwarf novae. SBS 1108+574, a peculiar hydrogen-rich dwarf nova below the period minimum, showed a very similar pattern of period variations to those of short-period SU UMa-type dwarf novae. The mass-ratio derived from the detected orbital period suggests that this secondary is a somewhat evolved star whose hydrogen envelope was mostly stripped during the mass-exchange. CC Scl, MASTER OT J072948.66+593824.4 and OT J173516.9+154708 showed only low-amplitude superhumps with complex profiles. These superhumps are likely a combination of closely separated two periods. Comment: 81 pages, 92 figures, PASJ in press, correction in the author list and text |
| Databáze: | OpenAIRE |
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