{
  "bibcode": "1999GCN...428....1U",
  "body": "R. Uglesich, J. Halpern (Columbia U.), & J. Thorstensen (Dartmouth)\nreport:\n\n\"In addition to the MDM observations reported in GCN #423, we\nreobserved the entire 6' radius error circle of the BeppoSAX WFC\n(Gandolfi, GCN #417) with the 1.3m because it is not known if either\nof the reported NFI X-ray sources (in 't Zand et al. GCN #427) is\nassociated with the GRB.  The 1.3m observations were centered on \nOct. 15.45 UT and Oct. 16.48 UT, and reach a  5-sigma limiting\nmagnitude of R = 22.6 on the first night, and R = 22.8 on the second \nnight.  We used a non-standard, broad R filter which nevertheless\ncalibrates very well with Landolt (1992) standards that we obtained.\nWe find R = 17.64 for the star mentioned in GCN #423, which is consistent\nwith the USNO calibration (R = 17.61 +/- 0.02).  Although we have not yet \ncarried out a detailed photometric analysis of the entire WFC circle,\ncareful visual inspection reveals no variable object to a limit of \napproximately R > 22.6 at 13 hours after the burst.  The images from\nthe MDM 2.4 reported in GCN #423 cover the error circles of both of \nthe NFI sources, and our previously reported limit of R > 23.1 at\n11.2 hours still applies.\n\nWe also note that Galactic extinction in this direction is estimated \nto be E(B-V) = 0.202 from IRAS dust maps (Schlegel et al. 1998),\nso A_R is a modest 0.54 magnitudes.\n\nA CCD image of the field of the NFI sources is posted at\nhttp://www.astro.bio2.edu/grb/\n\nThis message may be cited.\"",
  "circularId": 428,
  "createdOn": 940644694000,
  "email": "jules@astro.columbia.edu",
  "subject": "GRB 991014, Optical Observations",
  "submitter": "Jules Halpern at Columbia U.  <jules@astro.columbia.edu>",
  "eventId": "GRB 991014"
}