GCN Circular 3853
Subject
GRB050820A: RTT150 optical observations
Event
Date
2005-08-22T12:40:21Z (21 years ago)
From
Irek Khamitov at TUG <irekk@tug.tug.tubitak.gov.tr>
I. Bikmaev, A. Galeev, N. Sakhibullin (KSU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),
report:
We have observed the OT of GRB 050820A (GCN 3829) with the
Russian-Turkish 1.5-m telescope (Bakirlitepe, TUBITAK National
Observatory, Turkey) in two consequative nights .
We made a series of exposures in Rc between UT 18:35 - 22:15, August
20, 2005, and in BRcIc between UT 22:46-01:15, August 21/22, 2005.
Moonlight produced variable background in all images for both nights. The
afterglow is clearly detected in all bands. Using Henden's stars (GCN 3845)
present in the frames, we estimated the magnitudes as follow:
t-t0 Band mag merr exptime
(hours, midtime) (sec,total)
18.05 Rc 19.48 +/- 0.01 900
41.42 Rc 20.38 +/- 0.05 1800
40.93 B 21.00 +/- 0.06 1800
41.55 Ic 19.83 +/- 0.07 1800
On the basis of our Rc data, we estimeted an alpha index of power-law
decay for the observed period as ~ -1.0.
The JPG-images of BRcIc and color combined image are available at:
http://www.tug.tubitak.gov.tr/~irekk/grb/grb050820a/grb050820A_b.JPG
http://www.tug.tubitak.gov.tr/~irekk/grb/grb050820a/grb050820A_r.JPG
http://www.tug.tubitak.gov.tr/~irekk/grb/grb050820a/grb050820A_i.JPG
http://www.tug.tubitak.gov.tr/~irekk/grb/grb050820a/grb050820_bri.JPG
This message may be cited.