GCN Circular 6339
Subject
GRB 070419A: MARGE Observations
Date
2007-04-20T19:12:03Z (18 years ago)
From
Heather Swan at U.of Michigan/ROTSE <hflewell@umich.edu>
H. Swan (U Mich), I. Smith (Rice), C. Akerlof (U Mich), E. Rykoff (U
Mich), and M. Skinner (Boeing) report on behalf of the MARGE collaboration:
The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui
Space Surveillance System on Haleakala, observed the fading counterpart
to GRB070419A (Swift trigger 276205 (GCN 6302)). The images are
unfiltered 10s exposures which started at 10:57:41 UT (~58 minutes after
the trigger) and ended at 11:53:52 UT.
After coadding our images in sets of 10, we detect the OT first
identified by Chornock et al (GCN 6304). A preliminary analysis gives a
magnitude of approximately 20.5+/-0.2 at a mid time of 10:59:11 UT.
Using the SDSS data provided by Cool et al. (GCN 6318), we calibrate the
OT to the r band magnitude of the nearby 20.434 mag star located at
(J2000) RA = 182.73852, DEC = 39.93033. We find that the ABC data fades
as a power law decay with index ~-1.1, consistent with the
detections reported by Nishiura et al. (GCN 6308), Smith et al. (GCN
6315), Updike et al. (GCN 6317), Iizuka et al. (6317) (prior the ABC
observations) and Fu et al. (GCN 6311) (after the ABC observations).