GCN Circular 8337
Subject
GRB 081007: Early RAPTOR measurements of optical counterpart
Event
Date
2008-10-07T19:56:45Z (17 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman
of Los Alamos National Laboratory report:
The RAPTOR telescope system responded to Swift trigger
330856 (Baumgartner et al., GCN 8330) under fair observing conditions.
Our narrow-field instruments began observing the location at
05:24:17.13 UTC, 24.4 s after the Swift trigger and during the end
of the Gamma-Ray emitting interval. We detect the optical counterpart
reported by Baumgartner et al. (GCN 8330) and Covino et al. (GCN 8331).
We first detect the counterpart at R~16.4 at approximately 90s after
the Swift trigger time. The counterpart brightens over the next 50
seconds to magnitude R~15.4 and then begins fading steadily. Our
unfiltered images were calibrated against the USNO-B1 R-band. The
following table gives selected observations, not corrected for
extinction, from this event.
t-mid(s) exp(s) mag mag-err
--------------------------------------------
90.31 5.0 16.43 0.22
139.58 10.0 15.38 0.06
367.83 30.0 16.75 0.20
685.42 30.0 17.28 0.19