GCN Circular 9984
Subject
GRB 090926A: Skynet/PROMPT Observations of Day 4 - 6 Fading Rate
Date
2009-10-03T20:49:13Z (15 years ago)
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 has 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 in BVRI.
After peaking in brightness approximately 1 day after the trigger (Haislip
et al., GCN 9953), the afterglow had been fading with a power-law index of
approximately -1.4 until approximately 4 days after the trigger (Haislip,
et al., GCN 9982).
Between 4 and 6 days after the trigger, the afterglow has been fading with
a shallower power-law index of approximately -0.8.
At 6.1 days after the trigger, its magnitude is R = 20.40 +0.11 -0.10
(statistical) +/- 0.57 (systematic; calibrated to 172 USNO B1 stars).
Skynet's most recent BVRI light curve, calibrated to USNO B1 and NOMAD
stars, can be found here:
http://skynet.unc.edu/grb/grb090926a.jpg
