Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)
Creators: name: Kato, Taichi
name: Maehara, Hiroyuki
name: Uemura, Makoto
name: Henden, Arne
name: de Miguel, Enrique
name: Miller, Ian
name: Dubovsky, Pavol A.
name: Kudzej, Igor
name: Kiyota, Seiichiro
name: Hambsch, Franz-Josef
name: Tanabe, Kenji
name: Imamura, Kazuyoshi
name: Kunitomi, Nanae
name: Takagi, Ryosuke
name: Nose, Mikiha
name: Akazawa, Hidehiko
name: Masi, Gianluca
name: Nakagawa, Shinichi
name: Iino, Eriko
name: Noguchi, Ryo
name: Matsumoto, Katsura
name: Fujii, Daichi
name: Kobayashi, Hiroshi
name: Ogura, Kazuyuki
name: Ohtomo, Sachi
name: Yamashita, Kousei
name: Yanagisawa, Hirofumi
name: Itoh, Hiroshi
name: Bolt, Greg
name: Monard, Berto
name: Ohshima, Tomohito
name: Shears, Jeremy
name: Ruiz, Javier
name: Imada, Akira
name: Oksanen, Arto
name: Nelson, Peter
name: Gomez, Tomas L.
name: Staels, Bart
name: Boyd, David
name: Voloshina, Irina B.
name: Krajci, Thomas
name: Crawford, Tim
name: Stockdale, Chris
name: Richmond, Michael
name: Morelle, Etienne
name: Novak, Rudolf
name: Nogami, Daisaku
name: Ishioka, Ryoko
name: Brady, Steve
name: Simonsen, Mike
name: Pavlenko, Elena P.
name: Ringwald, Frederick A.
name: Kuramoto, Tetsuya
name: Miyashita, Atsushi
name: Pickard, Roger D.
name: Hynek, Tomas
name: Dvorak, Shawn
name: Stubbings, Rod
name: Muyllaert, Eddy
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.
description: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correction