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GCN Circular 473

GRB 991216, Optical Transient
1999-12-17T16:54:09Z (25 years ago)
Arne A. Henden at USNO/USRA <>
A. Henden (USRA/USNO), C. Luginbuhl, F. Vrba, H. Harris,
B. Canzian, J. Munn, S. Levine, H. Guetter (USNO), D. H.
Hartmann (Clemson Univ.), M.C. Jennings (IGPP, UCR visitor)

We confirm the fading optical source identified by
Halpern, et. al (GCN 472).  Accurate position from
a large set of USNO-A2.0 reference stars is
  05:09:31.29  +11:17:07.4 (J2000)
(internal error +/- 0.1arcsec)

R-band observations, referenced to the star at
05:09:39.30  +11:16:59.5 (J2000)

  UT     r    telescope
  0409  3.54   1.0-m
  0511  3.81   1.3-m
  0702  3.87   1.3-m

with photometric errors around 0.05mag.  It has
been non-photometric here for the past few weeks,
but as soon as the weather improves, we will calibrate
this field in UBVRI.

We have additional R-band and V-band data, and
will be observing this field again this evening.
Our infrared camera went on the 1.55-m this
morning, so we may attempt H-band observations
as well.
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