GCN Circular 6076
Subject
GRB 070208: ROTSE-III Optical Limits
Date
2007-02-08T10:13:07Z (17 years ago)
From
Fang Yuan at ROTSE <yuanfang@umich.edu>
F. Yuan (U Mich), W. Rujopakarn (U Arizona), H. Swan (U Mich), E. S.
Rykoff (U Mich) report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
070208 (Swift trigger 259714, GCN 6074, Sato, et al), producing images
beginning 5.8 s after the GCN notice time. An automated response took
the first image at 09:11:14.8 UT, 40.5 s after the burst, under fair
conditions. We took 10 5-sec, 10 20-sec and 20 60-sec exposures. These
unfiltered images are calibrated relative to USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within both
the BAT and the XRT error circles, for both single images and coadding
into sets of 10. We marginally detect one of the DSS objects detected by
Mirabal & Halpern (GCN 6075) in our deepest images. Individual images
have limiting magnitudes ranging from 15.9-17.0; we set the following
specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
09:11:14.8 09:11:19.8 5 16.0 40.5 N
09:11:14.8 09:12:21.9 67 17.5 40.5 Y
09:12:29.9 09:17:25.5 295 18.2 115.6 Y