[AAVSO-HEN] GRB 070411 : Liverpool Telescope Observations

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  6271
SUBJECT: GRB 070411 : Liverpool Telescope Observations
DATE:    07/04/11 23:22:35 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm at astro.livjm.ac.uk>

A. Gomboc (Univ. of Ljubljana, Slovenia), A. Melandri, C.G. Mundell,
I. A. Steele, D. Carter, M. Burgdorf, C. Guidorzi, A. Monfardini,
S. Kobayashi, D. Bersier (Liverpool JMU) and N. Tanvir (Leicester
University) report:


The 2-m Liverpool Telescope started observing the field of GRB070411
(Moretti et al. GCN 6267) in r'i'g' filters at 1 hr 20 min after the
trigger time.

We detect the optical candidate identified by Moretti et al. (GCN 6267),
Kann et al (GCN 6268), Rykoff et al. (GCN 6269) and Mikuz et al. (GCN 
6270)
in all filters.

We estimate the magnitude of the source to be R = 19.7 +/- 0.15 at
t = 1.36 hr and I = 19.0 +/- 0.3 at t = 1.43 hr after the trigger time.
Magnitudes were calibrated vs the USNOB1 catalogue.

Further analysis and observations are ongoing.