MAXI/GSC detection of a possible flare from an M dwarf binary EQ Peg
ATel #3107; T. Matsumura, A. Uzawa, Y. Tsuboi, K. Yamazaki, (Chuo U.), H. Tomida, S. Ueno, M. Kohama, M. Ishikawa (JAXA), T. Mihara, Y. E. Nakagawa, M. Sugizaki, M. Serino, T. Yamamoto, T. Sootome, M. Matsuoka (RIKEN), N. Kawai, M. Morii, K. Sugimori, R. Usui, T. Toizumi (Tokyo Tech), A. Yoshida, K. Yamaoka, S. Nakahira (AGU), H. Tsunemi, M. Kimura, H. Kitayama (Osaka U.), H. Negoro, M. Nakajima H. Ozawa, F. Suwa (Nihon U.), Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi (Kyoto U.), A. Daikyuji (Miyazaki U.), report on behalf of the MAXI team
on 14 Jan 2011; 16:41 UT
Credential Certification: Nobuyuki Kawai (nkawai@phys.titech.ac.jp)
Subjects: X-ray, Binary, Star, Transient
At a scan transit starting at 2011-01-13T06:38 (UT) (=MJD 55574.277), MAXI/GSC detected a transient X-ray source with a 4-10 keV flux of 80 +- 20 mCrab. The coordinates of the source were
(R.A., Dec.) = (353.06, 19.90) = (23h 32m 13s, +19d 54' 54") (J2000)
with statistical and systematic uncertainties of 0.1 and 0.2 degrees. Within the error circle is EQ Peg, an M dwarf binary at a distance of 6.25 pc. It is known to produce X-ray flares (Haisch et al. 1987, Pallavacini et al. 1990, Katsova 2002), and we tentatively identify it as the source of the transient X-ray emission.
The transient source decayed to 20 +- 10 mCrab at the following transit (08:15 UT), then brightened again to 40 +- 10 mCrab at 09:44 UT. The source was not detected at following transits with a typical upper limit of 20 mCrab.
