GCN Circular 17506
Subject
GRB 150222A: Further GROND Observations
Event
Date
2015-02-26T14:45:45Z (11 years ago)
From
Philip Wiseman at MPE/Swift <wiseman@mpe.mpg.de>
A. Nicuesa Guelbenzu (TLS Tautenburg), P. Wiseman, P. Schady and J.
Greiner (all MPE Garching) report on behalf of the GROND team:
We continued to observe the field of GRB 150222A (Swift trigger 632180;
Bernadini et al., GCN 17486) for a second night, simultaneously in
g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at
the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations began at 06:25:38 UT on February 24, ~34 hours after the
GRB trigger. They were performed at an average seeing of 1.3" and at an
average airmass of 1.1//.
In 106 min of total exposures in g'r'i'z', we detect a source in all
optical bands towards the north-eastern edge of the the 1.7" enhanced
Swift-XRT error circle (Beardmore et al., GCN 17494) , at a position
consistent with that reported in Nicuesa Guelbenzu et al. (GCN 17495).
In 115 min of total NIR exposures in the JHK bands, no source is
detected within the enhanced XRT error circle.
We detect no fading of the source between the two epochs, and therefore
suggest that this is not the afterglow, but could be the host galaxy
instead, unless we caught an afterglow plateau phase.