[vsnet-grb-info 8302] GRB 090817: Liverpool Telescope Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9827
SUBJECT: GRB 090817: Liverpool Telescope Observations
DATE:    09/08/18 18:56:21 GMT
FROM:    Zach Cano at ARI/John Moores Liverpool  <zec at astro.livjm.ac.uk>

GRB 090817: Liverpool Telescope Observations

Z. Cano,  I.A. Steele, C.G. Mundell,  A. Melandri, S. Kobayashi, C.J.
Mottram, R.J. Smith, D. Bersier (Liverpool JMU), A. Gomboc (U. Ljubljana),
report on behalf of a large collaboration:

On August 17 2009, 1.459 hours after the burst was detected, the 2-m
Liverpool Telescope automatically began observing the INTEGRAL GRB 090817
(Beckmann et al.,GCN Circ. 9815) using g',r' and i' filters.

We do not detect any uncatalogued source inside the Swift-XRT error circle
(Evans et al. GCN Circ 9819).  Upper limits in stacked R and I images for
isolated objects are 20.6 and 20.8 respectively.

Magnitudes have been calibrated from the nearby USNO star (1341-0096766):
04:15:52.314, +44:07:50.9 using R2=17.56 and I=17.04.

We note that the upper limits presented are the limits for detecting an
isolated object in our images.  As the USNO star (1341-0096763) lies only
1.3" from the XRT position the actual upper limits will be accordingly
brighter.