GCN Circular 82
Subject
GRB980519 Optical Observations
Event
Date
1998-05-20T19:55:36Z (28 years ago)
From
Eric Deutsch at U.Washington <deutsch@astro.washington.edu>
On behalf of the Apache Point Observatory GRB team, A. Diercks & C.
Stubbs observed with the APO 3.5m telescope the optical transient (OT)
discovered by Jaunsen et al. (GCN #78) in the BeppoSAX error box of GRB
980519. Conditions were mostly cloudy with roughly 1.8 arcsec seeing.
Photometry by E. Deutsch & A. Diercks on a 1 hr series of images
centered around May 20.44 UT yields the following magnitudes and
relative uncertainties for the OT and reference stars:
ID R mag RelErr
-- ----- -----
OT 21.20 0.03
A 17.93 0.01
B 19.31 0.01
C 18.06 0.01
Absolute calibration is based only on R magnitudes of reference stars
reported by Kemp & Halpern (GCN #80). No independent calibration was
possible due to heavy clouds. Our measurement is 0.3 mag fainter than
the earlier observations of Kemp & Halpern (GCN #80).
Images are posted at: http://www.astro.washington.edu/deutsch/grb/grb980519/
This note can be cited.