TITLE:   GCN CIRCULAR
NUMBER:  9953
SUBJECT: GRB 090926A: Skynet/PROMPT Continued Observations
DATE:    09/09/27 18:49:04 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 continued to observe the afterglow (Haislip et al., GCN 9937) of GRB 
090926A (Bissaldi, GCN 9933) with four of the 16" PROMPT telescopes at CTIO 
throughout the night in BVRI.

We find that the light curve brightens from the beginning of our 
observations (about 19 hours after the trigger) to about 1 day after the 
trigger in all bands, which is consistent with the findings of Oates & 
Vetere (GCN 9948) in UVOT's u band.

Around 1 day, the light curve peaks at R = 17.8 mag (calibrated to 82 USNO 
B1 stars) and begins to fade.  A second, smaller rebrightening begins 
around 26 hours and peaks at R = 18.0 mag around 27 hours.