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GCN Circular 458

GRB 991208, Optical Observation
1999-12-13T15:25:48Z (24 years ago)
Jules Halpern at Columbia U. <>
J. P. Halpern & D. J. Helfand (Columbia U.) report on behalf of the
MDM Observatory GRB follow-up team:

"We imaged the field of GRB 991208 in the R band on Dec. 13.53 UT
using the MDM 2.4m telescope.  A single 10 minute exposure was
obtained in non-photometric conditions.  The seeing was 1.1 arcseconds.
The afterglow was detected at R = 20.92 +/- 0.06, referenced to the
comparsion star quoted in GCNs 454 and 456 as having R = 15.9.
The decay index between our measurement and that of Garnavich &
Noriega-Crespo one day earlier (GCN 456) is -1.9 +/- 0.4.	

This message may be cited."
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