GCN Circular 10003
Subject
GRB 090926A: Skynet/PROMPT Observations of Day 6 - 11 Fading
Date
2009-10-09T17:24:40Z (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 two of the 16" PROMPT telescopes at
CTIO in RI.
After peaking in brightness approximately 1 day after the trigger (Haislip
et al., GCN 9953) and fading with a power-law index of around -1.4 until
approximately 4 days after the trigger (Haislip, et al., GCN 9982), the
afterglow faded with a shallower power-law index of around -0.8 until
approximately 6 days after the trigger (Haislip et al., GCN 9984).
Between 6 and 11 days after the trigger, the afterglow has been fading with
a steeper power-law index of around -1.7.
At 11.1 days after the trigger, its magnitude is R = 21.45 +0.22 -0.18
(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
Continued observations with larger telescopes are encouraged.
