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GCN Circular 341

X-ray/GRB 1SAX J0835.9+5118, Optical Observation
1999-05-22T08:23:45Z (25 years ago)
Christian B. Luginbuhl at USNO/Flagstaff <>
C. Luginbuhl (USNO), A. Castro-Tirado (LAEFF-INTA Madrid and IAA-CSIC
Granada), B. Canzian (USNO), E. Costa (IAS Frascati), J. Greiner (AIP
Potsdam), H. Guetter (USNO), A. Henden (USRA/USNO), M. Kuemmel (MPIA,
Heidelberg), S. Levine (USNO), J. Munn (USNO), S. Phleps (MPIA
Heidelberg), E. Pian (ITESRE Bologna), T. Rauch (Univ. of Tuebingen),
and F. Vrba (USNO)

report that a detailed comparison of R-band imaging described in GCN
336 (May 20.82 UT, limiting magnitude R=22.5) and GCN 339 (May 21.18
UT, limiting magnitude R=20.2), as well as additional imaging at the
Calar-Alto 2.2m telescope (May 21.82 UT, limiting magnitude R=21.5)
shows no variable objects at the three sigma level to approximately
R=21.5 within or near the 3-arcmin radius error circle of 1SAX
J0835.9+5118 (GCN 333).  Areas within about 2 arcmin of the error
circle are included in these images.  There is some further processing
that can be done that may improve the detection limits on the May 21.82
Calar-Alto image.

The object noted by Bloom et al. (GCN 335) continues to appear stellar,
with R=21.21 +/- 0.06.  The galaxy noted by Pedersen et al (GCN 340) is
clearly extended in these data, but shows no detail indicative of a
superposed star or SN, though our seeing was at best just 1.3 arcsec.

All photometric measures reported here are calibrated with the sequence
by Henden et al. (GCN 339).

This note can be cited.
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