[AAVSO-HEN] GRB 090809: WHT observations

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TITLE:   GCN CIRCULAR
NUMBER:  9762
SUBJECT: GRB 090809: WHT observations
DATE:    09/08/10 17:50:15 GMT
FROM:    Klaas Wiersema at U of Leicester  <kw113 at star.le.ac.uk>

K. Wiersema (Leicester), D. Malesani (DARK/NBI), A. Levan, D. Steeghs, L. van 
Spaandonk (Warwick) report on behalf of a larger collaboration:

We observed the field of GRB 090809 (Markwardt et al. GCN 9754) with the 
William Herschel Telescope using the ACAM instrument. Observations 
consisted of 4 x 300 second exposures with a sloan i filter, starting on 
August 9, 23:41 UT (6.16 hrs after burst). We clearly detect the afterglow 
(Markwardt et al. GCN 9754, Xu et al. GCN 9755) with i = 20.48 +/- 0.03 
(calibrated using SDSS stars).