TITLE:   GCN CIRCULAR
NUMBER:  32046
SUBJECT: GRB 220514B: MAXI/GSC detection
DATE:    22/05/15 00:43:04 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

 Y. Kawakubo (LSU), M. Serino (AGU), H. Negoro, 
 M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima (Nihon U.), 
 T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, M. Matsuoka (RIKEN), 
 T. Sakamoto, S. Sugita, H. Hiramatsu, A. Yoshida (AGU), 
 Y. Tsuboi, W. Iwakiri, J. Kohara (Chuo U.), 
 M. Shidatsu, M. Iwasaki (Ehime U.),
 N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech), 
 S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka, T. Kurihara (JAXA), 
 Y. Ueda, S. Ogawa, K. Setoguchi, T. Yoshitake, K. Inaba (Kyoto U.), 
 H. Tsunemi (Osaka U.), 
 M. Yamauchi, Y. Nonaka, T. Sato, R. Hatsuda, R. Fukuoka (Miyazaki U.), 
 K. Yamaoka (Nagoya U.),
 M. Sugizaki (NAOC)
 report on behalf of the MAXI team:
 
The MAXI/GSC nova alert system triggered a bright uncatalogued 
X-ray transient source at 23:24:21 UT on 2022 May 14.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (246.864 deg, 61.440 deg) = (16 27 27, +61 26 23) (J2000) 
with a statistical 90% C.L. elliptical error region 
with long and short radii of 0.26 deg and 0.24 deg, respectively. 
The roll angle of long axis from the north direction is 101.0 deg counterclockwise. 
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
Without assumptions on the source constancy, we obtain a rectangular error
box for the transient source with the following corners:
(246.141, 61.757) deg = (16 24 33, +61 45 25) (J2000) 
(245.940, 61.286) deg = (16 23 45, +61 17 09) (J2000) 
(248.119, 61.055) deg = (16 32 28, +61 03 17) (J2000) 
(248.352, 61.523) deg = (16 33 24, +61 31 22) (J2000) 
The X-ray flux averaged over the scan was 168 +- 26 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at 05/14 21:51 UT 
with an upper limit of 20 mCrab.