[vsnet-grb-info 6768] GRB 081008 optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8367
SUBJECT: GRB 081008 optical upper limit
DATE:    08/10/13 12:04:46 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt at aavso.org>

Peter Nelson (Ellinbank, Victoria, Australia) reports to the AAVSO 
International High Energy Network the following optical observation of 
GRB081008 (GCN #8344 Racusin et al.; GCN #8343 Rykoff et al.):

Peter Nelson has obtained a limiting magnitude on the optical afterglow of 
GRB081008 (Racusin et al., GCN #8344).  The optical afterglow position RA: 
18:39:50, Dec: -57:25:52 found by Rykoff et al. (GCN #8343) was observed 
for a total of 480 seconds using a 0.32-meter Newtonian with an SBIG ST8XE 
CCD and an R filter.  The mid-point of the observations was 2008 Oct 
09.4150 UT, approximately 14 hours after the burst.  The afterglow was not 
detected to an upper limit of R=18.2, using USNO-A2.0 star 0300-34687382 
(R=11.8) as the comparison.  This upper limit is consistent with the 
R-band magnitude of R=18.46 on 2008 Oct 08.9951 observed by Cobb et al. 
(GCN #8356).

A detailed report of these observations is available on the AAVSO website 
at ftp://ftp.aavso.org/grb/PeterNelson_081008_2454752.03073_.txt

A fits image is available at
ftp://ftp.aavso.org/grb/PeterNelson_081008_2454752.03073_.fits

The AAVSO thanks the Curry Foundation for their continued support of the 
AAVSO International High Energy Network.