GCN Circular 17912

M. Arimoto (Tokyo Tech), H. Negoro (Nihon U.),
S. Ueno, H. Tomida, S. Nakahira, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA),
T. Mihara, M. Sugizaki, M. Serino, M. Shidatsu, J. Sugimoto, T.
Takagi, M. Matsuoka (RIKEN),
N. Kawai, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech),
A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU),
H. Tsunemi, R.Imatani (Osaka U.),
M. Nakajima, K. Tanaka, T. Masumitsu (Nihon U.),
Y. Ueda, T. Kawamuro, T. Hori (Kyoto U.),
Y. Tsuboi, S. Kanetou (Chuo U.),
M. Yamauchi, D. Itoh (Miyazaki U.),
K. Yamaoka (Nagoya U.), M. Morii (ISM)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray
transient source at 11:46:50 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at

(R.A., Dec) = (13.389 deg, -0.213 deg) = (00 53 33, -00 12 46) (J2000)

with a statistical 90% C.L. elliptical error region
with long and short radii of 0.50 deg and 0.22 deg, respectively.
The roll angle of long axis from the north direction is 30.0 deg
counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90%
containment radius).

The X-ray flux averaged over the scan was 294 +- 58 mCrab
(4-10keV, 1 sigma error).

Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (12.424 deg, -0.277 deg) = (00 49 41, -00 16 37) (J2000)
(R.A., Dec) = (12.873 deg, 0.622 deg) = (00 51 29, +00 37 19) (J2000)
(R.A., Dec) = (14.875 deg, -0.382 deg) = (00 59 29, -00 22 56) (J2000)
(R.A., Dec) = (14.462 deg, -1.299 deg) = (00 57 50, -01 17 56) (J2000)
There was no significant excess flux in the previous transit at 6/8 10:14 UT.