GCN Circular 1651
Subject
GRB 020813; likely host galaxy.
Event
Date
2002-10-23T10:39:19Z (23 years ago)
Edited On
2024-11-18T09:51:39Z (a year ago)
From
Javier Gorosabel at LAEFF-INTA, Madrid <jgu@laeff.esa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
J. Gorosabel* (IAA-CSIC, Granada), J.P.U. Fynbo* (Univ. of Aarhus),
J. Hjorth, H. Pedersen, B.L. Jensen (Univ. of Copenhagen),
S.T. Holland* (Notre Dame), J.M. Castro Cerón* (ROA, San Fernando),
M. Andersen (AIP, Potsdam), A.J. Castro-Tirado (IAA-CSIC, Granada)
report:
We have imaged the GRB 020813 (GCN 1471) optical afterglow (GCN 1470)
with the 1.54-m Danish Telescope (+DFOSC) as follows:
===================================================================
Date Filter Seeing Exp.Time Time Since Mag
(UT) (") (s) GRB (days)
-------------------------------------------------------------------
10.01-10.13/10/2002 R 1.0 2x1200+8x900 58.0 23.90+/-0.14
09.02-09.17/10/2002 B 1.7 10x1200 57.0 24.46+/-0.19
-------------------------------------------------------------------
The calibration is based on the photometric standards given in GCN
1503. The B-R colour of our measurements (B-R=0.56+/-0.24) is bluer
than the ones reported for the afterglow to date (constant around
B-R ~ 1, see GCN 1513).
This "blueing" could be due to a change of spectral slope in the
afterglow or the presence of an underlying blue host galaxy.
Given the epoch of our observations (~60 days after the gamma-ray
event) we consider the second possibility more likely. The
faintness of our detection does not allow us to see any extended
structure.
Two gifs of the potential host galaxy can be seen at:
http://www.dsri.dk/~jgu/grb020813/GCN/grb020813R.gif
http://www.dsri.dk/~jgu/grb020813/GCN/grb020813B.gif
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* Visitors at the Copenhagen University Observatory.