GCN Circular 80
Subject
GRB980519 Optical Observations
Date
1998-05-20T15:11:30Z (27 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
The MDM Observatory GRB team (J. Kemp, J. Halpern) reports followup
photometry of the variable optical candidate discovered by Jaunsen et al.
(GCN #78) in the BeppoSAX error box of GRB 980519. In a series of CCD
images taken with the MDM 1.3m telescope, centered around May 20.31 UT,
the candidate had I=20.1+/-0.3, R=20.9+/-0.2. These magnitudes were
measured differentially with respect to stars A, B, and C of Jaunsen et
al., which we recalibrated using Landolt standards. Preliminary
photometry of those reference stars is as follows:
RA(2000) Dec(2000) R I
A 23 22 17.74 +77 15 51.2 17.93 17.28
B 23 22 27.29 +77 15 43.5 (19.26) (18.56)
C 23 22 28.50 +77 15 25.4 18.15 17.43
Parentheses indicate values that are less certain. Note the large
discrepancy between our I-band measurements and those of Jaunsen et al.;
the latter may instead refer to the V band.
MDM images will be posted at http://cba.phys.columbia.edu/jonathan/grb/.
This note can be cited.