[vsnet-grb-info 10662] GRB 110625A: ROTSE-III Optical Limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12089
SUBJECT: GRB 110625A: ROTSE-III Optical Limits 
DATE:    11/06/25 22:24:00 GMT
FROM:    Weikang Zheng at U.of Michigan  <zwk at umich.edu>

W. Zheng (U Mich) and W. Rujopakarn (Steward), report on behalf of the ROTSE
collaboration: 

ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe,
Turkey, responded to GRB 110625A (Swift trigger 456073; Page et al., GCN
12088), producing images beginning 6.8 s after the GCN notice time. An
automated response took the first image at 21:08:48.8 UT, 20.3 s after the
burst, and during the gamma-ray emission, under fair conditions. We took 10
5-sec, 10 20-sec and 110 60-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 15.5-16.6; we set the following specific limits. 

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?

--------------------------------------------------------------------

21:08:48.8   21:10:56.3       127     16.9           20.3       Y

21:11:05.2   21:15:42.8       277     17.5          156.7       Y

21:15:51.7   21:20:29.5       277     17.5          443.2       Y