GRB 050915A
GCN Circular 3990
Subject
GRB 050915a: IR Transient
Date
2005-09-16T14:52:12Z (20 years ago)
From
Josh Bloom at UC Berleley <jbloom@astron.berkeley.edu>
J. S. Bloom (UC Berkeley) reports:
"Further imaging of the field of GRB 050915a (GCNs 3977, 3979, 3983)
with the PAIRITEL 1.3m began at 2005-09-16 10:58:38 UTC. We confirm
that the source present in the first epoch (GCN 3984) has faded and
is thus the likely IR afterglow of GRB 050915a. In particular, the
mean H-band magnitude of the source during the first epoch was
H=18.25 +/- 0.16. The source was undetected in the second epoch, with
an approximate 3-sigma detection threshold of H(upper limit)=18.55 mag.
An improved astrometric solution was obtained for the imaging on
2005-09-15 UTC, yielding a J2000 position of the IRT of:
RA = 05:26:44.804
DEC = -28:00:59.27
The 1 sigma uncertainties relative to the 2MASS catalog are 0.18" and
0.09" in RA and DEC, respectively. This position is 3.2" from the
revised XRT position reported by Grupe et al. (GCN 3983).
We encourage deep z band and NIR imaging."
This message may be cited.
GCN Circular 4001
Subject
GRB 050915a: Radio Observations
Date
2005-09-19T12:14:54Z (20 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
P. B. Cameron (Caltech) and D. A. Frail (NRAO) report on behalf of a
larger collaboration:
"VLA observations were made toward the XRT position (GCN 3983) of
GRB 050915a at a frequency of 8.46 GHz on September 18.58 UT. No radio
sources are seen in the error circle above a 3-sigma level of 93 uJy.
The flux density at the position of the IR transient reported by
Bloom (GCN 3990) is 43 +/- 31 uJy.
No further observations are planned.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."