[vsnet-grb-info 7787] GRB 090509, SMARTS optical/IR afterglow observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9333
SUBJECT: GRB 090509, SMARTS optical/IR afterglow observations
DATE:    09/05/10 02:05:34 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb at astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 090509
(Grupe et al. GCN 9325) beginning approximately 0.8 hours post-burst
(2009-05-09 05:59 UT).  Several dithered images
were obtained in each filter, with total summed exposure times
of 180s in each of BRIJK and 120s in each of H and V.

The GRB afterglow (Olivares et al. GCN 9326, Covino et al. GCN 9327)
is detected in all filters with the following magnitudes
at a mid-exposure time of 2009-05-09 06:14 UT (1.07 hours
post-burst):

B= 20.18 +/- 0.13
V= 19.68 +/- 0.16
R= 19.02 +/- 0.10
I= 18.76 +/- 0.09
J= 17.70 +/- 0.16
H= 17.07 +/- 0.15
K= 16.48 +/- 0.22

(Optical photometry is calibrated against Landolt standard stars
 and IR photometry is calibrated against 2MASS stars in the field.)