{
  "bibcode": "2005GCN..3708....1C",
  "body": "B. E. Cobb and C. D. Bailyn (Yale), part of the larger SMARTS\nconsortium, report:\n\nUsing the ANDICAM instrument on the 1.3m telescope at CTIO, we\nobtained optical/IR imaging of the error region of GRB 050730\n(GCN 3704, Holland et al.) with a mid-exposure time of\n2005-07-30 23:05 UT, which is ~3.1 hours post-burst.\nTotal summed exposure times amounted to 15 minutes in I and V and\n12 minutes in J and K.\n\nThe candidate afterglow (Holland et al, GCN 3704,\nSota et al. GCN 3705, Gomboc et al. GCN 3706) is\nwell detected in our images.\n\nAssuming the nearby USNO-B1.0 star 0862-0270654\nhas a magnitude of I = 17.6 (USNO-B1.0 I2 magnitude)\nand J = 16.4 (2MASS magnitude), then the magnitude \nof the afterglow candidate is I ~ 17.2 and J ~ 16.3\nin the total combine frames.\n\nThe afterglow candidate also shows strong evidence of decay\nbetween successive frame.  Preliminary analysis suggests\nthat the afterglow may have decayed in I by \n~ 0.5 magnitudes between the first and last frame taken\nover a 40 minute period.  Given this evidence of decay, \nthis source is very likely the optical afterglow\nof GRB 050730.",
  "circularId": 3708,
  "createdOn": 1122772024000,
  "email": "cobb@astro.yale.edu",
  "subject": "GRB 050730, SMARTS optical/IR afterglow observations",
  "submitter": "Bethany Cobb at Yale U  <cobb@astro.yale.edu>",
  "eventId": "GRB 050730"
}