GCN Circular 6476

Subject

GRB 070531: Liverpool Telescope Optical Observations

Event

Date

2007-05-31T03:55:08Z (18 years ago)

From

Andreja Gomboc at LT,ARI,Liverpool JMU <ag@astro.livjm.ac.uk>

A. Gomboc (Univ. of Ljubljana), R.J. Smith, C.G. Mundell, A. Melandri, 
I.A. Steele, D. Carter, A. Monfardini, C.J. Mottram, S. Kobayashi, D. 
Bersier, M. Burgdorf (Liverpool JMU) and C. Guidorzi 
(Uni-Bicocca/INAF-OAB) report:

The 2-m Liverpool Telescope robotically followed up GRB 070531 (Swift 
trigger 280958, GCN 6475Loading...
 
  Markwardt et al.) and started observing the field 
at 3.7 min after the trigger time with the RINGO polarimeter. Photometric 
observations started at 11.9 min after the trigger time.

In first images we do not detect any new object down to:

Filter        t_mid  (min from GRB)     Tot_Exp (s)      Lim
-------------------------------------------------------------------
r'                 13.2                  60              18.2
i'                 19.0                 120              17.9
------------------------------------------------------------------
Magnitudes were calibrated vs R2 and I mag from the USNOB1 catalogue.
Further analysis is ongoing.