{
  "bibcode": "2000GCN...904....1Z",
  "body": "GRB 001212 Optical Observation\n\nJ. Zhu, on behalf of the Beijing Astronomical Observatory GRB team, report:\n\n\"The approximately one degree square field centered with GRB 001212 error\nbox (Hurley et al., GCN 899) was imaged again with the 0.6/0.9-m Schmidt\ntelescope (Zhu et al., GCN 903) during Dec. 15.51-15.54, 15.69-15.76, and\nDec. 16.56-59 under good weather condition. Three 1200-s exposures \n(limiting magnitude for each is about R=21) and nine 600-s exposures were \ntaken in Dec. 15 and three 960-s exposures in Dec. 16. The source \nmentioned by Mohan et al. (GCN 900) was clearly detected in all images, \nand there seems to be no obvious variation at the level of photometric\naccuracy (0.2-0.3 mag).\n\nUsing the following four USNO-A V1.0 objects (David Monet, et. al.)\n\n================================\nNo.     RA (2000.0) Dec     mag.\n--- ----------------------- ----\n1   06:49:30.03 +36:24:35.5 14.6\n2   06:49:31.16 +36:23:30.6 14.9\n3   06:49:32.45 +36:22:12.1 14.3\n4   06:49:32.63 +36:21:06.1 14.1\n================================\n\nas our magnitude references (the real procedure is to use R=14.475 for\nthe average magnitude of the above 4 stars), the magnitudes derived\nfrom each frame are (combined with two previous images mentioned in\nGCN 903 for completeness; photometric error is one-sigma):\n\n=============================\nDate   mag  error    notes\n----  ----- ----- -----------\n14.63 17.66 1.52  bad weather\n14.64 16.91 0.68  bad weather\n15.51 18.69 0.14\n15.53 18.72 0.14\n15.54 18.39 0.13\n15.69 18.39 0.18\n15.70 18.60 0.22\n15.71 18.97 0.28\n15.72 18.55 0.19\n15.73 18.82 0.26\n15.73 18.64 0.22\n15.74 19.20 0.37\n15.75 18.71 0.24\n15.76 18.64 0.23\n16.56 18.84 0.16\n16.58 18.58 0.14\n16.59 18.57 0.17\n=============================\n\nWe conclude that this object is not optical afterglow for GRB 001212.\"\n\nThis message may be cited.\n\n-- \n========================================================================\nJin Zhu                          | Tel.:  +86-10-62751286 (O)\nBeijing Astronomical Observatory |        +86-314-5054767 (Schmidt dome)\nChinese Academy of Sciences      | Pager: +86-10-96301682333\nP. R. China                      | Fax :  +86-10-62765031\n------------------------------------------------------------------------\nRoom 2919, No. 2 Science Building, CAS-PKU Beijing Astrophysics Center,\nPeking University, Beijing 100871, P. R. CHINA.\n------------------------------------------------------------------------\nemail: zj@bac.pku.edu.cn                  http://vega.bac.pku.edu.cn/~zj\n========================================================================",
  "circularId": 904,
  "createdOn": 976980809000,
  "email": "zj@bac.pku.edu.cn",
  "subject": "GRB 001212 Optical Observation",
  "submitter": "Jin Zhu at BAO  <zj@bac.pku.edu.cn>",
  "eventId": "GRB 001212"
}