학술논문
Superoutburst of SDSS J090221.35+381941.9: First Measurement of Mass Ratio in an AM CVn-Type Object using Growing Superhumps
Document Type
Working Paper
Author
Kato, Taichi; Ohshima, Tomohito; Denisenko, Denis; Dubovsky, Pavol A.; Kudzej, Igor; Stein, William; de Miguel, Enrique; Henden, Arne; Miller, Ian; Antonyuk, Kirill; Antonyuk, Oksana; Pit, Nikolaj; Sosnovskij, Aleksei; Baklanov, Alex; Babina, Julia; Pavlenko, Elena P.; Matsumoto, Kazunari; Fukushima, Daiki; Takenaka, Megumi; Kawabata, Miho; Daisuke, Daisuke; Maeda, Kazuki; Matsuda, Risa; Matsumoto, Katsura; Littlefield, Colin; Oksanen, Arto; Itoh, Hiroshi; Masi, Gianluca; Nocentini, Francesca; Schmeer, Patrick; Pickard, Roger D.; Kiyota, Seiichiro; Dvorak, Shawn; Ulowetz, Joseph; Maeda, Yutaka; Michel, Raul; Shugarov, Sergey Yu.; Chochol, Drahomir; Novak, Rudolf
Source
Subject
Language
Abstract
We report on a superoutburst of the AM CVn-type object SDSS J090221.35+381941.9 [J0902; orbital period 0.03355(6) d] in 2014 March-April. The entire outburst consisted of a precursor outburst and the main superoutburst, followed by a short rebrightening. During the rising branch of the main superoutburst, we detected growing superhumps (stage A superhumps) with a period of 0.03409(1) d. During the plateau phase of the superoutburst, superhumps with a shorter period (stage B superhumps) were observed. Using the orbital period and the period of the stage A superhumps, we were able to measure the dynamical precession rate of the accretion disk at the 3:1 resonance, and obtained a mass ratio (q) of 0.041(7). This is the first successful measurement of the mass ratio in an AM CVn-type object using the recently developed stage A superhump method. The value is generally in good agreement with the theoretical evolutionary model. The orbital period of J0902 is the longest among the outbursting AM CVn-type objects, and the borderline between the outbursting systems and systems with stable cool disks appears to be longer than had been supposed.
Comment: 6 pages, 4 figures, accepted for publication in PASJ
Comment: 6 pages, 4 figures, accepted for publication in PASJ