[vsnet-grb-info 8007] GRB 090618: RTT150 optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9548
SUBJECT: GRB 090618: RTT150 optical observations
DATE:    09/06/22 09:50:24 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 OT (Schady et al., GCN 9512; Cenko et al., GCN 9513; Perley,
GCN 9514; Rujopakarn et al., GCN 9515) of the Swift GRB 090618 with
Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National
Observatory, Turkey), in BRc bands, starting at 22 Jun, 00:03 UT,
i.e. approximately 3.65 days after the burst, using TFOSC.
  
We made 3x900s exposures in Rc band and 2x900 in B band. The OT is detected
in all images. Using the same USNO-B1 star as it was used by Rumyantsev and
Pozanenko (GCN 9539) we estimate Rc magnitude as m_Rc=21.60+/-0.04 (3.68
days after the burst).

The finding chart can be found at:

http://hea.iki.rssi.ru/grb/090618/indexeng.html