[vsnet-grb-info 8480] GRB 090926B: Skynet/PROMPT Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9996
SUBJECT: GRB 090926B: Skynet/PROMPT Observations
DATE:    09/10/06 04:07:49 GMT
FROM:    Josh Haislip at U.North Carolina  <haislip at physics.unc.edu>

J. Haislip, D. Reichart, K. Ivarsen, A. LaCluyze, 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 090926B (Grupe et al., 
GCN 9935) with four of the 16" PROMPT telescopes at CTIO beginning 2.7 
hours after the trigger in UVRI.

We do not detect the afterglow (Grupe et al., GCN 9935; Malesani, Fynbo & 
D'Elia, GCN 9944).  Stacking only images that increase the limiting 
magnitude yields:

mean                                                1-sig.  1-sig.
time                            3-sig.              sys.    stat.
since                           lim.    cal.        cal.    cal.
trig.  tel.      exp.     fil.  mag.    stars       unc.    unc.
(h)              (# x s)                            (mag)   (mag)

2.7    PROMPT-4  4 x 80   R     19.9    40 USNO B1  0.424   0.002
2.7    PROMPT-2  4 x 80   V     18.2    11 NOMAD    0.099   0.003
2.7    PROMPT-5  3 x 80   I     18.2    32 USNO B1  0.414   0.003