{
  "circularId": 2336,
  "bibcode": "2003GCN..2336....1D",
  "createdOn": 1059508790000,
  "eventId": "XRF 030723",
  "body": "Second Epoch Magellan Observations of XRF030723 (=H2777)\n\nA. Dullighan, N. Butler, R. Vanderspek, J. Villasenor,  and G. Ricker\n(MIT)\n\nwrite:\n\nWe have observed the SXC error circle for the HETE-discovered X-ray\nflash XRF030723 (=H2777; Prigozhin et al, GCN 2313) with the MagIC\ninstrument on the 6.5m Magellan Clay telescope at Las Campanas\nObservatory in Chile. Two 200 second, Harris R-band exposures were taken\nin an interval centered on July 28.385 UT, at 5.13 days after the\nburst.  The seeing was ~0.8 arcsec. Coaddition of the images gives a\nlimiting magnitude of R = 24.3.\n\nWe detect the optical counterpart (Fox et al., GCN 2323) of GRB 030723\nat R = 24.2 +/- 0.3.  Combining our photometry with that available from\nthe GCN Circulars (Bond, GCN 2329; Dullighan et al., GCN 2326; Fox et al.,\nGCN 2323), we estimate a late time power law decay index of ~2, and an\nearly power law decay of 0.9.  The break in the light curve is between\n30-50 hours after the burst.  Our measurements have been calibrated\nagainst the USNO photometry data reported by Henden in GCN 2317.\n\nA plot of this light curve can be seen at:\n\n  http://space.mit.edu/HETE/Bursts/GRB030723/\n\nWe gratefully acknowledge observational assistance by Matthew J. Holman\nand Jeff McClintock.\n\nThis message may be cited.",
  "submitter": "Roland Vanderspek at MIT  <roland@space.mit.edu>",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "email": "roland@space.mit.edu",
  "subject": "XRF030723 (=H2777):  Second Epoch Magellan Observations",
  "editedOn": 1777052923780,
  "version": 2
}