{
  "bibcode": "2010GCN.10359....1S",
  "body": "M. Suzuki (JAXA), H. Negoro (Nihon U.), M. Morii, K. Sugimori, N.Kawai\n(Tokyo Tech), M. Matsuoka, K. Kawasaki, S. Ueno, H. Tomida, M. Ishikawa\n(JAXA), T. Mihara, M. Kohama, Y.E. Nakagawa, M. Sugizaki, T. Yamamoto\n(RIKEN), A. Yoshida, K. Yamaoka, S. Nakahira (AGU), H. Tsunemi, M.\nKimura (Osaka U.), M. Nakajima, S. Miyoshi, H. Ozawa, R. Ishiwata,(Nihon\nU.), Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi (Kyoto U.) report on behalf\nof the MAXI team:\n\nAt the scan transit centered at UT 2010-02-02T17:14:52, MAXI/GSC\ndetected a transient X-ray source, which was present at least for 15\nseconds within the 110 seconds triangular transit response of MAXI/GSC.\n\nThe nominal location of the source, assuming that the source flux was\nconstant over the transit (which probably was not), is determined as\n\n(R.A., Dec)=(261.05 deg, -32.94 deg) = (17 24 12, -32 56 24) (J2000)\n\nwith a rectangular 90% statistical error box with the following corners:\n\n(R.A., Dec)= (261.11 deg, -33.27 deg) = (17 24 26, -33 16 12)(J2000)\n(R.A., Dec)= (260.75 deg, -33.23 deg) = (17 23 00, -33 13 48)(J2000)\n(R.A., Dec)= (261.00 deg, -32.67 deg) = (17 24 00, -32 40 12)(J2000)\n(R.A., Dec)= (261.36 deg, -32.72 deg) = (17 25 26, -32 43 12)(J2000)\n\nThe systematic uncertainties are calibrated using bright sources found\nin the same scan, and therefore, are much smaller.\n\nIf the source was only temporarily bright during the scan, which is well\nexpected for the case of a GRB/XRF or an X-ray burst, uncertainty along\nthe scan direction becomes larger, as we cannot fit the light curve to\nthe triangular transit response. Without assumptions on the source\nconstancy, we obtain a rectangular error box with the following corners:\n\n(R.A., Dec)= (260.33 deg, -34.11 deg) = (17 21 19, -34 06 36)(J2000)\n(R.A., Dec)= (260.81 deg, -34.15 deg) = (17 23 14, -34 09 00)(J2000)\n(R.A., Dec)= (261.89 deg, -31.74 deg) = (17 27 34, -31 44 24)(J2000)\n(R.A., Dec)= (261.43 deg, -31.67 deg) = (17 25 43, -31 40 12)(J2000)\n\nThe nominal flux (4-10 keV) of the source was about 120 mCrab if the\nsource was constant over the transit. The flux could be 300 mCrab or\nhigher if the emission was present only for 15 seconds within the\ntransit.  There was no significant detection at this location in the\nprevious and following orbits (92 min before or after the detection)\nwith an upper limit of 20 mCrab.  There is no known bright X-ray binary\nsource at the detected position.  At the galactic coordinates\n(l,b)=(354.1, 1.7), the source is likely to be Galactic, although\nextragalactic origin cannot be ruled out.\nWith a very preliminary spectral analysis, the energy spectrum can be\nmodeled by a highly absorbed (NH>1e23 cm-2) blackbody  (kT~1.5 keV),\nsuggestive of a type-1 X-ray burst at a large distance.\n\nThe scan light curve and the source location will be posted at the MAXI\nweb site http://maxi.riken.jp at the news section.\n\nNote:  Since the nature of the source is unknown, this message is\ncross-posted to ATel and GCN.",
  "circularId": 10359,
  "createdOn": 1265216820000,
  "email": "nkawai@hp.phys.titech.ac.jp",
  "subject": "Short X-ray Transient detected by MAXI/GSC",
  "submitter": "Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>"
}