[vsnet-grb-info 8008] GRB 090621B: RTT150 optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9549
SUBJECT: GRB 090621B: RTT150 optical observations
DATE:    09/06/22 09:55:15 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion at hea.iki.rssi.ru>

A. Galeev, I. Bikmaev, N. Sakhibullin (KSU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Khamitov, Z. Eker (TUG), U. Kiziloglu (METU),  E. Gogus (Sabanci Uni.)

report:

We observed the field of the Swift-BAT GRB 090621B (Curran et al., GCN9545)
with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National
Observatory, Turkey), starting at 21 Jun, 22:52:55 UT, i.e. approximately 45
minutes after the burst, using TFOSC. 

We made 3x300s exposures in Rc band. On combined image we do not detect any
new source inside the XRT error circle (Curran et al., GCN 9545) besides the
source reported by Levan et. al. (GCN 9547), which is detected only
marginally. There is also one more brighter point-like source
(RA=20:53:51.25, DEC=+69:01:37.4, J2000) outside but close to the edge of
XRT error circle. Using USNO-B1 stars we estimate its magnitude as
m_Rc=21.8+/-0.06. The limiting magnitude of combined image is m_Rc ~23.6.

The finding chart can be found at:

http://hea.iki.rssi.ru/grb/090621b/indexeng.html