{
  "bibcode": "1999GCN...217....1Z",
  "body": "GRB 990123 Optical Follow-Up\n\nJ. Zhu, J. S. Chen, and H. T. Zhang, on behalf of the Beijing Astronomical\nObservatory GRB team report:\n\n\"We observed the GRB 990123 OT (GCN #202) during Jan. 24.730-24.861 with\nBAO 0.6-m Schmidt telescope under non-photometric weather. Combination of\ntwo relatively best quality 60-min. images taken with BATC band-i filter\n(central wavelength at 6660 A, band width 480 A) gives a detection of \nthe object (OT+galaxy) at RA=15:25:30.17, Dec=+44:45:59.7 (J2000) with \nmagnitude of 21.0 +/- 0.3 (Jan 24.818) using the No. 1 and No. 2 stars in\nGCN #204. No visual seperation between OT and galaxy could be recognized\nbecause of low S/N ratio and bad spatial resolution (1 pixel = 1.7\",\nseeing = 5.6\"). Central 4' X 4' part of the whole 58' X 58' CCD field\nwill soon be available under \nhttp://vega.bac.pku.edu.cn/~zj/grb/grb990123.html\n\nRe-reduction of GCN #204 observation with only first 2 of the 4 stars\ngives same result for the OT+galaxy in magnitude of 19.2 +/- 0.1 (Jan\n23.756).\n\nThis report may be cited.\"",
  "circularId": 217,
  "createdOn": 917252371000,
  "email": "grb@bac.pku.edu.cn",
  "subject": "GRB 990123 Optical Follow-Up",
  "submitter": "Jin Zhu at Beijing Obs  <grb@bac.pku.edu.cn>",
  "eventId": "GRB 990123"
}