GCN Circular 1823
Subject
GRB030115: R-band counterpart of IR candidate
Date
2003-01-16T16:53:59Z (22 years ago)
From
Nicola Masetti at IASF,CNR,Bologna <masetti@bo.iasf.cnr.it>
N. Masetti, E. Palazzi (IASF/CNR, Bologna), E. Pian (INAF - Astron. Obs.
of Trieste), S. Covino (INAF - Astron. Obs. of Brera) and L.A. Antonelli
(INAF - Astron. Obs. of Rome), on behalf of a larger Italian collaboration,
report:
"A more accurate inspection of our R-band observation (Masetti et al.,
GCN #1811) of the HETE/SXC error box of GRB030115 (Kawai et al.,
GCN #1816) shows a faint object at the position of the variable K-band
object (Levan et al., GCN #1818).
We measure for this object a magnitude R ~ 21.5, assuming R = 16.7 for the
closeby USNO star U1050_06471524.
A count excess at the position of this object appears to be present on the
DSS2-Red also, suggesting that any R-band variability at the time of
GRB030115 must be of low amplitude. The positional coincidence with the IR
transient however strengthens the reality of this object even if it is
close to the detection limit in both DSS2 and our R-band images.
This object might be the host galaxy if the IR source is indeed
the GRB afterglow. If this is true, the non-detection of a bright
afterglow in the optical might be more likely due to a very high local
extinction, rather than to the high redshift.
The optical counterpart to the radio source detected by Berger et al.
(GCN #1817) is well detected on both the DSS2 and our R-band frame
as an extended object with magnitude R ~ 20.
This message is citeable.".