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GCN Circular 303

GRB 990506, Optical Observations
1999-05-09T03:10:15Z (25 years ago)
Jules Halpern at Columbia U. <>
R. Uglesich and B. Sugerman (Columbia U.) report:

We obtained R-band images of the refined RXTE/IPN error region of GRB 990506 
(Hurley et al. GCN #298) using the MDM Observatory 1.3m and a CCD covering a 
10.7 x 10.7 arcmin field.  On the nights of May 7 UT and May 8 UT, seeing was 
approximately 1.3 and 1.5 arcseconds, respectively.  Exposure times were
75 minutes on the first night and 100 minutes on the second.  The Landolt 
standard star field of PG 1047+003 was used for calibration.  The object at 
(J2000) 11:54:57.8, -26:43:03.8, which was reported as possibly variable by
Vrba et al. (GCN #300), is measured at R = 22.43 +/- 0.15 on May 7.2, and
R = 22.38 +/- 0.18 on May 8.2, thus confirming the conclusions of Vreeswijk
& Rol (GCN 301) and Garnavich et al. (GCN #302) that it is not variable. 

[GCN OP NOTE (10May99):  At the author's request (JH), the last sentence
(of a humorous perspective) of the originally submitted circular was removed 
from this archived copy, as it does not follow the content guidelines
of the Circulars.]
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