TITLE:   GCN CIRCULAR
NUMBER:  17461
SUBJECT: GRB 150211A: ROTSE-III Upper Optical Limit
DATE:    15/02/12 22:49:20 GMT
FROM:    Farley V. Ferrante at Southern Methodist U/ROTSE  <fferrante@smu.edu>

F. V. Ferrante (SMU), T. Guver (Istanbul U), G. Dhungana (SMU), R. Staten (SMU)

and R. Kehoe (SMU) report on behalf of the ROTSE GRB team:

The 0.45-m ROTSE-IIIb telescope, located at McDonald Observatory, Texas,

responded to GRB 150211A (Swift trigger 630714; Starling, et al.,GCN 17434) with

imaging beginning 3.8 s after the GCN notice time. An automated response recorded

the first image at 11:52:43.8 UT, 30.7 s after the burst, under fair observing conditions.

The unfiltered images are calibrated relative to USNO A2.0 (R). We do not detect an

optical source within the refined Swift-XRT error circle (Starling et al., GCN 17442).

We set the following upper limit:


start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
-----------------------------------------------------------------------------------------------
11:52:43.8   11:53:43.8      60       17.6           30.7               N