TITLE:   GCN CIRCULAR
NUMBER:  9921
SUBJECT: Short-Duration GRB 090916: Skynet/PROMPT Observations
DATE:    09/09/17 02:52:44 GMT
FROM:    Josh Haislip at U.North Carolina  <haislip@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 short-duration GRB 090916 
(Troja et al., GCN 9913) with four of the 16" PROMPT telescopes at CTIO 
beginning 2.6 hours after the trigger in UVRI through high airmass.

We do not detect any uncatalogued sources.  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-3   6 x 80   U      17.7     14 SDSS 7   1.137    0.011
2.7     PROMPT-2   6 x 80   V      18.8     88 SDSS 7   0.020    0.001
2.7     PROMPT-5   6 x 80   I      18.6     56 SDSS 7   0.073    0.000
2.7     PROMPT-4   6 x 80   R      19.4     44 SDSS 7   0.005    0.000

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