GCN Circular 10077
Subject
GRB 091024: TLS Upper Limit
Date
2009-10-25T05:59:03Z (15 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann, and U. Laux (TLS Tautenburg) report:
We observed the afterglow of the ultra-long Swift/GBM GRB 091024 (Marshall
et al., GCN 10062, Mundell et al., GCN 10063, Bissaldi & Connaughton, GCN
10070) with the 1.34m Schmidt telescope of the Thueringer
Landessternwarte Tautenburg, Germany, 0.6 days after the GRB. We obtained
6 x 600 sec images in Rc.
As a comparison star, we use the USNOB1.0 star at:
RA (J2000) = 22:37:31.11
Dec. (J2000) = +56:59:26.23
which has R2 = 17.78 mag. This was one of the rare non-blended stars that
was bright enough to be detected in the catalog.
At the afterglow position, we do not detect any source which is not
detected anyway in the DSS2 red plate. We place the following 2 sigma
upper limit on the afterglow:
dt Filter UL
____________________________________
0.602309 Rc 21.0
and note that the true upper limit may be less deep due to crowding (the
afterglow pretty much conincides with a ~20th mag object detected in the
DSS).
No further observations are planned.
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