GCN Circular 164
Subject
GRB 981220
Date
1998-12-23T20:06:07Z (25 years ago)
From
Fredrick J. Vrba at USNO <fjv@nofs.navy.mil>
GRB 981220 I-Band Observations
The U.S. Naval Observatory GRB team (C. B. Luginbuhl, F. J. Vrba,
A. A. Henden, S. E. Levine, J. Munn, B. Canzian, H. H. Guetter),
D. H. Hartmann (Clemson Univ.), and M. C. Jennings (IGPP, UCR visitor)
report I-band observations of the GRB 981220 localization formed
by the intersection of the RXTE (GCN 159) and IPN (GCN 160) error
boxes. Observations were obtained with the USNO 1.55-m telescope on
UT 1998 December 23 consisting of 6 dithered 10-min exposures
taken between UT 06:05:50 and UT 07:21:06 with a Tek 2K CCD having a
field of view of approximately 6x6 arcmin. The combined, median filtered,
and high-pixel rejected image can be viewed at the USNO public website:
http://www.nofs.navy.mil/news/grb/grb981220.html. Although the seeing
was rather poor (1.5-1.8 arcsec, FWHM), each of the 10-min exposures
is deeper than the Digital Sky Survey POSS-I image and reveals many more
objects than on the DSS. No obvious counterpart is revealed in comparing
to the DSS image. Additionally, the six frames were blinked to
search for variable objects, but none were obvious.
This GCN note can be cited.