GCN Circular 10262
Subject
GRB 091208B: Faulkes Telescope North and South Optical Afterglow
Date
2009-12-08T13:52:33Z (14 years ago)
From
Zach Cano at ARI/John Moores Liverpool <zec@astro.livjm.ac.uk>
Z. Cano, A. Melandri, C.G. Mundell (Liverpool JMU), A. Gomboc (U.
Ljubljana), D. Bersier, N.R. Clay, S. Kobayashi, C.J. Mottram, R.J. Smith,
I.A. Steele (Liverpool JMU), C. Guidorzi (U. Ferrara) report on behalf of
a large collaboration:
The 2-m Faulkes Telescopes North and South robotically followed up
GRB091208B (SWIFT trigger 378559; Pagani et al. GCN 10256) beginning 1.78
min after the GRB trigger time. We detect the optical afterglow in BRi'
filters at the location reported by de Ugarte Postigo et al. (GCN 10255)
and Pagani et al. (GCN 10256).
We derive the following preliminary magnitudes wrt USNOB1:
Filter Mag Merr T-To (s)
-------------------------------------------
R 17.75 0.02 572
R 18.48 0.03 1656
I 17.51 0.05 1036
I 18.34 0.04 3749
From our observations we derive a power-law decay constant of ~ 0.6 for
both filters.
We have not corrected our magnitudes for the small amount of foreground
reddening along the line of sight (E(B-V) = 0.05, corresponding to Av =
0.17 (Schlegel et al. 1998)).
Observations and analysis are ongoing.
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