[vsnet-grb-info 16364] GRB 150220A: Optical observations at Kyiv comet station

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17645
SUBJECT: GRB 150220A: Optical observations at Kyiv comet station
DATE:    15/03/26 13:05:37 GMT
FROM:    Valentyna Golovnya at Main Astro Obs,Kyiv  <golov_v at ukr.net>

Ya. Romanyuk (Main Astro Obs., Kyiv), A. Baransky (Astr. Obs. of Kyiv
University), I. Kulyk, V. Golovnya, V. Andruk (Main Astro Obs., Kyiv)
report:

We observed the field of GRB 150220A (P.A. Evans, GCN Circ. 17501) with
0.7-m f/4 reflector of Kyiv comet station (Marsden's number – 585).
The telescope is equipped with CCD, 1027ï‚´1056 pixels with a scale of
0.95"/px. We obtained 21ï‚´60sec images in R-filter on Mar., 10, 2015,
from (UTC) 19:08:15 to 19:44:09. Purpose of our observations was not to
search for the afterglow candidate. We would like to find two objects
referred to in (V. V. Golovnya, V. M. Andruk, GCN 17589), which was 
found on the old archive photographic plates in close vicinity of the
position of source '1SXPS J090208.3-014021':

RA,Dec(J2000)= 09h02m12.961s  -01d40'24.457"
        and    09 02 13.504   -01 39 51.118
The preview of archive photographic plates can be found at
'http://gua.db.ukr-vo.org/img/grb/150220A/index.html'    

The CCD images were processed with the standard technique and co-added
together to create a frame with higher signal/noise ratio. We did not 
find above mentioned objects on the CCD, but we confirmed some of the
positions reported early by P.A. Evans (GCN 17501). The following table
gives the positions listed by Evans, as well as the positions some 
of the objects calculated from the CCD.

Position from P. A. Evans, GCN 17501          our work
RA(J2000)          Dec(J2000)             RA(J2000)      Dec(J2000)
1) 09h 01m 31.65s -01° 39' 07.6" -------- outside our field
2) 09h 01m 30.74s -01° 38' 27.0" -------- outside our field
3) 09h 02m 08.55s -01° 36' 59.1" -------- 09h 02m 08.1s -01° 36' 35"
4) 09h 02m 08.90s -01° 40' 20.1" -------- extremely faint 
5) 09h 01m 28.27s -01° 39' 06.3" -------- outside our field
6) 09h 02m 25.29s -01° 41' 14.9" -------- 09h 02m 25.3s -01° 41' 15"
7) 09h 01m 46.37s -01° 38' 13.9" -------- 09h 01m 46.4s -01° 38' 14"