1108.5252 (Taichi Kato et al.)

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. III: The Third Year (2010--2011)    [PDF]

Taichi Kato, Hiroyuki Maehara, Ian Miller, Tomohito Ohshima, Enrique de Miguel, Kenji Tanabe, Kazuyoshi Imamura, Hidehiko Akazawa, Nanae Kunitomi, Ryosuke Takagi, Mikiha Nose, Franz-Josef Hambsch, Seiichiro Kiyota, Elena P. Pavlenko, Aleksei V. Baklanov, Oksana I. Antonyuk, Denis Samsonov, Aleksei Sosnovskij, Kirill Antonyuk, Maksim V. Andreev, Etienne Morelle, Pavol A. Dubovsky, Igor Kudzej, Arto Oksanen, Gianluca Masi, Thomas Krajci, Roger D. Pickard, Richard Sabo, Hiroshi Itoh, William Stein, Shawn Dvorak, Arne Henden, Shinichi Nakagawa, Ryo Noguchi, Eriko Iino, Katsura Matsumoto, Hiroki Nishitani, Tomoya Aoki, Hiroshi Kobayashi, Chihiro Akasaka, Greg Bolt, Jeremy Shears, Javier Ruiz, Sergey Yu. Shugarov, Drahomir Chochol, Nikolai A. Parakhin, Berto Monard, Kazuhiko Shiokawa, Kiyoshi Kasai, Bart Staels, Atsushi Miyashita, Donn R. Starkey, Yenal Ogmen, Colin Littlefield, Natalia Katysheva, Ivan M. Sergey, Denis Denisenko, Tamas Tordai, Robert Fidrich, Vitaly P. Goranskij, Jani Virtanen, Tim Crawford, Jochen Pietz, Robert A. Koff, David Boyd, Steve Brady, Nick James, William N. Goff, Koh-ichi Itagaki, Hideo Nishimura, Youichirou Nakashima, Seiichi Yoshida, Rod Stubbings, Gary Poyner, Yutaka Maeda, Stanislav A. Korotkiy, Kirill V. Sokolovsky, Seiji Ueda

Continuing the project described by Kato et al. (2009, PASJ 61, S395, arXiv:0905.1757), we collected times of superhump maxima for 51 SU UMa-type dwarf novae mainly observed during the 2010-2011 season. Although most of the new data for systems with short superhump periods basically confirmed the findings by Kato et al. (2009) and Kato et al. (2010, PASJ 62, 1525, arXiv:1009.5444), the long-period system GX Cas showed an exceptionally large positive period derivative. An analysis of public Kepler data of V344 Lyr and V1504 Cyg yielded less striking stage transitions. In V344 Lyr, there was prominent secondary component growing during the late stage of superoutbursts, and the component persisted at least for two more cycles of successive normal outbursts. We also investigated the superoutbursts of two conspicuous eclipsing objects: HT Cas and the WZ Sge-type object SDSS J080434.20+510349.2. Strong beat phenomena were detected in both objects, and late-stage superhumps in the latter object had an almost constant luminosity during the repeated rebrightenings. The WZ Sge-type object SDSS J133941.11+484727.5 showed a phase reversal around the rapid fading from the superoutburst. The object showed a prominent beat phenomenon even after the end of the superoutburst. A pilot study of superhump amplitudes indicated that the amplitudes of superhumps are strongly correlated with orbital periods, and the dependence on the inclination is weak in systems with inclinations smaller than 80 deg.

View original: http://arxiv.org/abs/1108.5252