MAXI/GSC detection of an X-ray flare from the BY Dra type star HD 29697
ATel #17335; W. Iwakiri (Chiba U.), H. Negoro, M. Nakajima, K. Takagi, H. Takahashi, H. Nishio (Nihon U.), T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, H. Hiramatsu, Y. Kondo, A. Yoshida (AGU), Y. Tsuboi, H. Sugai, N. Nagashima, Y. Ishihara (Chuo U.), M. Shidatsu, Y. Niida, C. Kang, T. Nakamoto (Ehime U.), I. Takahashi, Y. Yatsu (Science Tokyo), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA), Y. Ueda, K. Fujiwara (Kyoto U.), M. Yamauchi, M. Nishio, C. Hiraizumi (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (Kanazawa U.), T. Kawamuro (Osaka U.), S. Yamada (Tohoku U), report on behalf of the MAXI team:
on 16 Aug 2025; 00:36 UT
Credential Certification: Wataru Iwakiri (iwakiri@chiba-u.jp)
Subjects: X-ray, Star, Transient
The MAXI/GSC nova alert system triggered on an X-ray flare from the position consistent with the BY Dra type star HD 29697 during a scan transit at 21:35 UT on Aug 15 2025.
The X-ray flux averaged over the scan was 74 +/- 19 mCrab
(4.0-10.0keV, 1 sigma error). Since the distance to the source is 13.2123 pc (GaiaCollaboration et al.2020), the observed X-ray flux corresponds to a luminosity of about 3 x 1031 erg/s.
There was no significant excess flux with an upper limit of 20 mCrab in the next scan transit 23:08 UT.
This is the first time that MAXI has detected an X-ray flare from HD 29697 in 16 years of observation.
