GCN Circular 4404
Subject
GRB 051227: R-band object in the XRT error circle
Event
Date
2005-12-28T05:39:12Z (20 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
D. Malesani (SISSA), S. Piranomonte, L.A. Antonelli (INAF/OAR), E.
Depagne, C. Lidman, C. Melo (ESO), S. Campana, S. Covino, G. Tagliaferri
(INAF/OABr), G. Chincarini (Univ. Milano-Bicocca), M. Della Valle
(INAF/OAA), F. Fiore, and L. Stella (INAF/OARm), report on behalf of the
MISTICI collaboration:
We observed the field of the hard (and possibly short) GRB 051227
(Barbier et al., GCN 4397; Barthelmy et al., GCN 4401; Sakamoto et al.,
GCN 4403) using the ESO VLT-UT2 (Kueyen) equipped with the FORS1
instrument. Observations started on 2005 Dec 28, 04:22 UT (~10.3 h after
the GRB), in the R band. Observations were conducted at high airmass and
moderate seeing (1.5").
Coadding three 5-min images, we detect inside the revised XRT error
circle (Beardmore et al., GCN 4402) one single, faint source, at the
coordinates (J2000):
alpha = 08:20:58.14
delta = +31:55:31.7
The astrometric error is about 0.5". This object is not seen in the
r-band SDSS images provided by Cool et al. (GCN 4399). However, it is
significantly fainter than the limit of these images. We propose this
object as a candidate afterglow or host for GRB 051227.
We also note a further, fainter object slightly outside the XRT error
circle, at the coordinates:
alpha = 08:20:57.54
delta = +31:55:32.47
We acknowledge the excellent support from the ESO staff.