[AAVSO-HEN] GRB 070521: SARA upper limit

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TITLE:   GCN CIRCULAR
NUMBER:  6445
SUBJECT: GRB 070521: SARA upper limit
DATE:    07/05/22 00:21:31 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike at clemson.edu>

A. C. Updike, J. R. Puls, and D. H. Hartmann (Clemson University) report 
on behalf of the Clemson GRB Follow-Up Team:

We imaged the field of GRB 070521 (GCN 6431, Guidorzi et al.) beginning 
14 minutes after the trigger (279935) with the SARA 0.9m at Kitt Peak 
under decent weather conditions.  In 50 minutes of stacked exposures in 
the R band, we detect no new sources in the XRT error circle down to a 
limiting magnitude of 20 +/- 0.4.  We do not detect the source noted by 
Hattori et al. (GCN 6444).  This magnitude is based on calibration to 5 
USNO B1.0 stars.

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 http://saraobservatory.org

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