GCN Circular 9357
Subject
GRB 090515: ROTSE-III Optical Limits
Date
2009-05-15T05:08:31Z (15 years ago)
From
Wiphu Rujopakarn at U AZ/Steward <wiphu@as.arizona.edu>
W. Rujopakarn (Steward Observatory), B. E. Schaefer (Louisiana State), and
E.S. Rykoff (UCSB), report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
090515 (Swift trigger 352108; Beardmore et al., GCN 9356), producing
images beginning 6.5 s after the GCN notice time. An automated response
took the first image at 04:45:27.5 UT, 18.0 s after the burst, under fair
conditions. We took 10 5-sec and 10 20-sec exposures. These unfiltered
images are calibrated relative to USNO A2.0 (R). Imaging is on going.
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle or the XRT error circle, for both single
images and coadding into sets of 10. Individual images have limiting
magnitudes ranging from 16.4-17.8; we set the following specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
04:45:27.5 04:45:32.5 5 16.4 18.0 N
04:45:27.5 04:46:34.6 67 18.4 18.0 Y