{
  "bibcode": "1999GCN...315....1A",
  "body": "Tim Axelrod, Jeremy Mould,  and Brian Schmidt (Research School of Astronomy\nand Astrophysics, The Australian National University) report the following\noptical photometry of GRB990510 using\nthe Mount Stromlo 50inch + Macho Camera (measured with respect to the USNO\nstar at RA = 13:38:00.82, DEC=-80:29:11.7  for which we have assumed\nR = 17.2, cf. Galama et al GCN 313). The following observations are Macho R\n(effective lambda = 700nm), but transform almost identically to R_c.\n\n      R mag     err   May (UT)   Telescope    \n\n      18.24     0.02   10.514  MSO 50inch\n      18.31     0.02   10.522  MSO 50inch\n      18.30     0.02   10.529  MSO 50inch\n      19.23     0.07   10.775  MSO 50inch\n      19.31     0.07   10.783  MSO 50inch    \n      19.25     0.04   10.791  MSO 50inch    \n\n\nThe absolute uncertainty in the calibration is not included. The decay\nis consistent with a power law, with temporal decay index -0.88 +- 0.03.\n\nSimultaneous observations in Macho-B (effective lambda = 510nm)\nshow a powerlaw decay of index -0.94 +- 0.04.\n\nThis message is citeable.\n\n\n[GCN OP NOTE:  This circular was received at 20:26 11 May 99 UT,\nbut was delayed in distribution due to not having a prior vetting account.]",
  "circularId": 315,
  "createdOn": 926427364000,
  "email": "brian@mso.anu.edu.au",
  "subject": "GRB990510",
  "submitter": "Brian Schmidt at Australian Nat. U.  <brian@mso.anu.edu.au>",
  "eventId": "GRB 990510"
}