GCN Circular 12198
Subject
GRB 110726A: Liverpool Telescope observations
Date
2011-07-26T03:37:41Z (13 years ago)
From
Andrea Melandri at Liverpool John Moores U <axm@astro.livjm.ac.uk>
A. Melandri (INAF-OAB), D. Bersier and R. Smith (Liverpool JMU)
report on behalf of a large collaboration:
The 2-m Liverpool Telescope robotically followed up GRB110726A (SWIFT
trigger 458059; Wolf et al. GCN 12196) starting 190 seconds after the
GRB trigger time. Initial RINGO2 polarimeter frames detected no
candidate optical transient. Switching to broad band imaging, we do
detect an uncatalogued source inside the XRT error circle, consistent
wih the proposed optical counterpart of Schaefer et al. (GCN Circ.
12197), in all three SDSS-gri filters. Our preliminary photometry gives:
Mid time from Total Exp Filter Magnitude
trigger (min) (s)
------------------------------------------------
14.7 10 R 19.0 +/- 0.1
30.0 60 R 19.6 +/- 0.1
20.1 30 I 18.6 +/- 0.1
33.0 60 I 19.1 +/- 0.1
------------------------------------------------
The observed decay is rather shallow (power law index ~0.4) for the
next 45 minutes, unlike the initial behavior observed by ROTSE.
Magnitudes have been calibrated from the nearby USNOB-1 stars.
Observations still ongoing.