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GCN Circular 351

Optical Observations of GRB 990506
1999-06-15T18:34:56Z (25 years ago)
Josh Bloom at CIT <>
Optical Observations of GRB 990506

J. S. Bloom, S. G. Djorgovski, S. R. Kulkarni, and B. A. Jacoby (Caltech),
on behalf of the Caltech-NRAO-CARA GRB collaboration, report:

"On June 11.25 UT, we obtained a total of 1500-s R-band integration of the
field of GRB 990506 (Hurley et al.; GCN #290) with the Low-Resolution
Imaging Spectrometer (LRIS) on the Keck II 10-m telescope on Mauna Kea,
Hawaii. An astrometric plate solution was obtained relative to the USNO
A2.0 catalog with a statistical error of 0.23, 0.26 arcsec (ra, dec).
Coincident with the position of the fading radio source (Taylor et al.;  
GCN #350) is a faint extended (NE-SW) galaxy with an irregular (and
possibly interacting) morphology.  Assuming the star at ra: 11:54:54.7,
dec: -26:41:15.2 (J2000) has R=18.5 (Henden et al; GCN #305), we find a
preliminary magnitude of the presumed host galaxy of GRB 990506 to be
R=24.8 +/- 0.2.

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