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GCN Circular 338

X-ray/GRB 1SAX J0835.9+5118, Optical Observation
1999-05-21T08:50:48Z (25 years ago)
Jules Halpern at Columbia U. <>
J. P. Halpern (Columbia U.), R. Barr (MDM), & E. Costa (IAS/CNR, Rome)
report on behalf of the MDM Observatory GRB follow-up team:

"We imaged the field of the BeppoSAX fast X-ray transient 1SAX J0835.9+5118
(Piro GCN 333, Gandolfi et al., IAUC 7174) in the B band starting on 
May 21.15 UT using the MDM 1.3m.  Total exposure time was 50 minutes in
seeing of 1.2 arcseconds.  Astrometry was performed with respect to 24 stars 
from the USNO A2.0 catalogue yielding an rms dispersion of 0.32 arcseconds.
A limiting magnitude of approximately B = 22.5 was reached, referenced to the 
magnitudes listed for two stars in USNO A2.0 catalogue, denoted here A and B:

Star        RA(2000)     Dec(2000)     B mag
A        08 35 53.669  +51 18 30.72    16.4
B        08 36 04.485  +51 17 26.46    18.5
Radio    08 36 01.11   +51 17 06.7     20.9

Also listed is the location and preliminary magnitude of the object which is 
coincident with the revised radio source position of Frail et al. (GCN 337).  
Although referred to as a galaxy in that circular and in GCN 335, it appears 
point-like in our images, as was also noted by Castro-Tirado et al. (GCN 336) 
from their R-band images.  No other objects of note appear in our images.

R-band images were also obtained by observers on the MDM 2.4m.
Results of these will be reported later.

This message may be cited."
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