[AAVSO-HEN] GRB 090920: Skynet/DSO Detection

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  10109
SUBJECT: GRB 090920: Skynet/DSO Detection
DATE:    09/10/29 21:38:15 GMT
FROM:    Aaron LaCluyze at U.North Carolina  <lacluyze at physics.unc.edu>

LaCluyze, A., D. Reichart, A. Smith, D. Caton, L. Hawkins, J. Haislip, K. 
Ivarsen, R. Egger, A. Foster, J. Moore, A. Oza, M. Schubel, J. Styblova, A. 
Trotter, J. A. Crain, and M. Nysewander report:

Skynet observed the Swift/BAT localization of GRB 090920 (Racusin et al., 
GCN 10048) with the 14" Dark Sky Observatory telescope in North Carolina 
beginning 12.0 hours after the trigger in I.

We detect the afterglow (Racusin et al., GCN 10048).  Stacking only images 
that increase the limiting magnitude yields:

mean                                                         1-sig.  1-sig.
time                                                         sys.    stat.
since                                             cal.       cal.    cal.
trig.  tel.    exp.      fil.  magnitude          stars*     unc.    unc.
(h)            (# x s)                                       (mag)   (mag)

12.6   DSO-14  18 x 160  I     19.75 +0.26 -0.21  13 SDSS 7  0.020   0.001

* Transformed using Jester et al., 2005, ApJ, 130, 873.