MAXI/GSC detection of a large X-ray flare from the dMe star AT Mic
ATel #12748; R. Sasaki, W. Iwakiri (Chuo U.), C. Gio (RIKEN), Yohko Tsuboi, H. Kawai, T. Sato (Chuo U.), H. Negoro, M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), S. Nakahira, T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, H. Nishida, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), M. Shidatsu (Ehime U.), N. Kawai, M. Sugizaki, M. Oeda, K. Shiraishi (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, M. Tominaga (JAXA), Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, S. Iwahori, Y. Kurihara (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU) report on behalf of the MAXI team:
on 12 May 2019; 07:29 UT
Credential Certification: Wataru Iwakiri (wataru.iwakiri@riken.jp)
Subjects: X-ray, Star, Transient
The MAXI/GSC nova alert system triggered on the flare-like event at 2019-05-12 04:45 (UT). Since the dMe star AT Mic is the only known X-ray source in the MAXI error region, we concluded that this is an X-ray flare from AT Mic. The observed peak X-ray flux is 450 +/- 40 mCrab (1 sigma error) in the 4 - 10 keV band. The peak spectrum is well reproduced by a distribution of thermal emission with a temperature kT = 7.4 +5.2, -2.4 keV. Assuming a distance of 10.2 pc, the peak luminosity is 1.4 x 1032 erg/s. This is the largest AT Mic flare ever observed by the MAXI/GSC.
