GCN Circular 310

P.M. Vreeswijk, T.J. Galama, E. Rol (U. of Amsterdam), K. Pollard
(U. of Canterbury), J. Menzies (SAAO), P. Sackett (U. of Groningen),
K. Sahu (STScI), J. van Paradijs (U. of Amsterdam and U. of Alabama in
Huntsville), and C. Kouveliotou (USRA/MSFC) report on behalf of the
PLANET microlensing team and the Amsterdam/Huntsville GRB optical
follow-up team:

"We have observed the error box of GRB 990510 (Dadina et al. 1999; IAU
Circular 7160) with the Sutherland 1.0m telescope (South Africa) in B
and R (several exposures of 1200 sec) on May 10.72 UT. Comparison of
the images with the DSS (2nd Epoch Survey of the UK Schmidt; RG610
filter) reveals a bright object at RA 13:38:07.62, DEC -80:29:48.8
(J2000; estimated positional uncertainy of about 2"), which is not
detected in the DSS. By comparison with a couple of USNO stars we
estimate R = 19.2 +- 0.3. We strongly urge further observations to be
made of this possible GRB counterpart."

A finding chart can be found at http://www.astro.uva.nl/~titus/grb990510.html

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