A big flare from UV Ceti
ATel #6026; M. Ishikawa (JAXA), Uchida (Osaka U.) A. Kawagoe, Y. Tsuboi (Chuo U.), S. Ueno, H. Tomida, S. Nakahira, M. Kimura, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Morii, M. Serino, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), N. Kawai, R. Usui, T. Yoshii, Y. Tachibana (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Nakano, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, M. Sasaki (Osaka U.), H. Negoro, M. Nakajima, K. Fukushima, T. Onodera, K. Suzuki (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), M. Higa (Chuo U.), M. Yamauchi, K. Yoshidome, Y. Ogawa, H. Yamada, Y. Morooka (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team:
on 30 Mar 2014; 14:58 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Yohko Tsuboi (tsuboi@phys.chuo-u.ac.jp)
Subjects: X-ray, Star, Variables
On 2014-03-29 15:21 (UT) UT (=MJD 56745.640), the MAXI/GSC transient alert system triggered on enhanced X-ray emission at
(R.A., Dec) = (24.687 deg, -18.012 deg) = (01 38 44.88, -18 00 43.2) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.12 deg and 0.11 deg respectively.
The roll angle of long axis from the north direction is 24.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
This position is consistent with a dMe star, UV Ceti.
The 2-20 keV flux averaged over the 44-second triangular transit was about 580 mCrab, corresponding to a luminosity of 9 × 10 30 ergs/s for an assumed distance of 2.6 pc. The flux decayed to an upper limit of ~20 mCrab at the next scan performed 92 minutes later. This flare from UV Ceti is the 3rd detection with MAXI/GSC, and is
the largest among the three flares.
