GCN Circular 11716

H. Negoro, M. Nakajima, H. Ozawa, F. Suwa (Nihon U.), N. Kawai, M. Morii, 
K. Sugimori, R. Usui, T. Toizumi (Tokyo Tech), M. Serino, T. Mihara, 
Y.E. Nakagawa, M. Sugizaki, T. Yamamoto, T. Sootome, M. Matsuoka (RIKEN),
K. Kawasaki, S. Ueno, H. Tomida, M. Kohama, M. Ishikawa (JAXA),
A. Yoshida, K. Yamaoka,  S. Nakahira (AGU), H. Tsunemi, M. Kimura (Osaka U.),
Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi (Kyoto U.), A. Daikyuji (Miyazaki U.), 
A. Uzawa, T. Matsumura, K. Yamazaki (Chuo U.) report on behalf of the MAXI team:

MAXI/GSC triggered at UT 2011-02-13T14:31:48 on a bright uncatalogued X-ray 
transient source.  Judging from its location and spectral hardness ratio, 
this transient is probably a gamma-ray burst. 
Since the emission was detected only for a fraction of the triangular 
transit response, the uncertainty of its position along the scan direction 
is large.  The center of the error box is 

(R.A., Dec) = (+41.768,  0.952 deg) = (02 47 04,  00 57 07)(J2000)

with an uncertainty of 0.5 deg (90% containment radius).
The preliminary flux of the transient source was 1.3 Crab (2-4 keV),
2.2 Crab (4-10 keV), and 3.5 Crab (10-20 keV).
There was no significant detection at the transit location in the
previous orbit (92 min before the detection) with an upper limit of 20 mCrab.  
There is no known bright X-ray source at the detected position. 

Follow-up observations are encouraged.