TY - JOUR
TI - Survey of period variations of superhumps in su UMa-type dwarf novae
AU - Kato, T.
AU - Imada, A.
AU - Uemura, M.
AU - Nogami, D.
AU - Maehara, H.
AU - Ishioka, R.
AU - Baba, H.
AU - Matsumoto, K.
AU - Iwamatsu, H.
AU - Kubota, K.
AU - Sugiyasu, K.
AU - Soejima, Y.
AU - Moritani, Y.
AU - Ohshima, T.
AU - Ohashi, H.
AU - Tanaka, J.
AU - Sasada, M.
AU - Arai, A.
AU - Nakajima, K.
AU - Kiyota, S.
AU - Tanabe, K.
AU - Imamura, K.
AU - Kunitomi, N.
AU - Kunihiro, K.
AU - Taguchi, H.
AU - Koizumi, M.
AU - Yamada, N.
AU - Nishi, Y.
AU - Kida, M.
AU - Tanaka, S.
AU - Ueoka, R.
AU - Yasui, H.
AU - Maruoka, K.
AU - Henden, A.
AU - Oksanen, A.
AU - Moilanen, M.
AU - Tikkanen, P.
AU - Mika, A.H.O.
AU - Monard, B.
AU - Itoh, H.
AU - Dubovsky, P.A.
AU - Kudzej, I.
AU - Dancikova, R.
AU - Vanmunster, T.
AU - Pietz, J.
AU - Bolt, G.
AU - Boyd, D.
AU - Nelson, P.
AU - Krajci, T.
AU - Cook, L.M.
AU - Torii, K.
AU - Starkey, D.R.
AU - Shears, J.
AU - Jensen, L.-T.
AU - Masi, G.
AU - Hynek, T.
AU - Novák, R.
AU - Kocián, R.
AU - Král, L.
AU - Kučáková, H.
AU - Kolasa, M.
AU - Šťastný, P.
AU - Staels, B.
AU - Miller, I.
AU - Sano, Y.
AU - Ponthière, P.D.E.
AU - Miyashita, A.
AU - Crawford, T.
AU - Brady, S.
AU - Santallo, R.
AU - Richards, T.
AU - Martin, B.
AU - Buczynski, D.
AU - Richmond, M.
AU - Kern, J.
AU - Davis, S.
AU - Crabtree, D.
AU - Beaulieu, K.
AU - Davis, T.
AU - Aggleton, M.
AU - Morelle, E.
AU - Pavlenko, E.P.
AU - Andreev, M.
AU - Baklanov, A.
AU - Koppelman, M.D.
AU - Billings, G.
AU - Urbančok, L.
AU - Ögmen, Y.
AU - Heathcote, B.
AU - Gomez, T.L.
AU - Voloshina, I.
AU - Retter, A.
AU - Mularczyk, K.
AU - Złoczewski, K.
AU - Olech, A.
AU - Kedzierski, P.
AU - Pickard, R.D.
AU - Stockdale, C.
AU - Virtanen, J.
AU - Morikawa, K.
AU - Hambsch, F.-J.
AU - Garradd, G.
AU - Gualdoni, C.
AU - Geary, K.
AU - Omodaka, T.
AU - Sakai, N.
AU - Michel, R.
AU - Cárdenas, A.A.
AU - Gazeas, K.D.
AU - Niarchos, P.G.
AU - Yushchenko, A.V.
AU - Mallia, F.
AU - Fiaschi, M.
AU - Good, G.A.
AU - Walker, S.
AU - James, N.
AU - Douzu, K.-I.
AU - Julian II, W.M.
AU - Butterworth, N.D.
AU - Shugarov, S.Yu.
AU - Volkov, I.
AU - Chochol, D.
AU - Katysheva, N.
AU - Rosenbush, A.E.
AU - Khramtsova, M.
AU - Kehusmaa, P.
AU - Reszelski, M.
AU - Bedient, J.
AU - Liller, W.
AU - Pojmański, G.
AU - Simonsen, M.
AU - Stubbings, R.
AU - Schmeer, P.
AU - Muyllaert, E.
AU - Kinnunen, T.
AU - Poyner, G.
AU - Ripero, J.
AU - Kriebel, W.
JO - Publications of the Astronomical Society of Japan
PY - 2009
VL - 61
TODO - SPEC. ISS. 2
SP - S395-S616
PB - Oxford University Press
SN - 0004-6264, 2053-051X
TODO - 10.1093/pasj/61.sp2.s395
TODO - Surveys;  Stars, Accretion: accretion disks;  Cataclysmic variables;  Dwarf novae;  Evolutionary stage;  Late stage;  Long lasting;  Mass ratio;  Orbital periods;  Stars: dwarf novae;  Stars: novae: cataclysmic variables, Stars;  Surveys
TODO - We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution of the superhump period is found to be composed of three distinct stages: an early evolutionary stage with a longer superhump period, a middle stage with systematically varying periods, and a final stage with a shorter, stable superhump period. During the middle stage, many systems with superhump periods of less than 0.08 d show positive period derivatives. We present observational characteristics of these stages and give greatly improved statistics. Contrary to an earlier claim, we found no clear evidence for a variation of period derivatives among different superoutbursts of the same object. We present an interpretation that the lengthening of the superhump period is a result of the outward propagation of an eccentricity wave, which is limited by the radius near the tidal truncation. We interpret that late-stage superhumps are rejuvenated excitation of a 3:1 resonance when superhumps in the outer disk are effectively quenched. The general behavior of the period variation, particularly in systems with short orbital periods, appears to follow a scenario proposed in Kato, Maehara, and Monard (2008, PASJ, 60, L23). We also present an observational summary of WZ Sge-type dwarf novae. Many of them have shown long-enduring superhumps during a post-superoutburst stage having longer periods than those during the main superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to be strongly correlated with the fractional superhump excess, or consequently with the mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with multiple rebrightenings tend to have smaller period derivatives, and are excellent candidates for those systems around or after the period minimum of evolution of cataclysmic variables. © 2009. Astronomical Society of Japan.
ER -