Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 11730

GRB110213A: RAPTOR Early Optical Peak and Plateau Measurements
2011-02-14T23:04:03Z (13 years ago)
James Wren at LANL <>
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis,
of Los Alamos National Laboratory report:

The RAPTOR telescope system responded to Swift trigger 445414
(V. D'Elia et al., GCN 11705) under fair observing conditions. Our
narrow-field instruments began observing the location at 05:17:58.2 UTC,
28.7 seconds after the initial BAT trigger.  We detect the optical
counterpart at the location reported by the Swift UVOT team.  The
counterpart brightens from below our threshold at around 100 seconds
after the BAT trigger.  It reaches a peak magnitude of 14.7 at T~300 s.
The counterpart then begins a steady decline to magnitude 16.0 at
T~2000 s.  At that point, the counterpart re-brightens to a plateau at
roughly magnitude 15.8 for about an hour before resuming the fading
behavior.  The following table gives a sample of our observations:

t-mid(s)    exp(s)     mag     mag-err
143.80      10.0      15.23    0.03
352.60      10.0      14.68    0.02
2179.60     30.0      16.12    0.03
4522.90     30.0      15.58    0.03
7172.30     30.0      16.00    0.04

The unfiltered images were calibrated against the USNO-B1 R-band.
Looking for U.S. government information and services? Visit