[vsnet-grb-info 14576] GRB 140219A: Mondy optical observations of XRT source #5

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15890
SUBJECT: GRB 140219A: Mondy optical observations of XRT source #5
DATE:    14/02/28 14:57:36 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A.Volnova (IKI), A. Pozanenko (IKI), I. Korobtsev (ISTP), E. Klunko 
(ISTP),  M. Eselevich (ISTP), report on behalf of larger GRB follow-up 
collaboration:

We observed the field of possible XRT afterglow candidate (Mangano et 
al., GCN 15875) of the GRB 140219A (Hurley et al., GCN 15864, Zhang GCN 
15866, Guiriec et al.,GCN 15867, Golenetskii et al. GCN 15870, Serino et 
al. GCN 15882) with AZT-33IK telescope of Mondy observatory on Feb. 22 
(UT) 14:45-15:45 (Pozanenko et al., GCN 15876) and Feb. 27 (UT) 
15:18-16:18. We obtained several images with exposure of 60 seconds in 
R-filter during each observational set. In the stacked images within XRT 
error circle (Mangano et al., GCN 15875) we clearly detect two objects 
which are present in SDSS plates and SDSS DR9. One of them is a galaxy 
(refereed below as G5), SDSS J102406.58+062945.8, and other one is a 
star (X5), SDSS J102406.41+062937.6, both objects mentioned earlier 
(Pozanenko et al.,  GCN 15876, Singer et al.,  GCN 15878).
No new objects were detected.

The photometry of the two sources is following:

date         UT start t-T0      Exp.    Filter  G5     X5
                      (mid, days) (s)
2014-02-22  14:45:44  2.81197    51*60  R 20.77+/-0.12 19.74+/-0.05
2014-02-27  15:18:29  7.81388    60*60  R 20.51+/-0.09 19.59+/-0.06

The photometry is based on reference stars SDSS-DR9, (R mag,
transformation by Lupton 2005):

N  SDSS_id                R(Lupton)   err
1  J102410.32+062923.9    17.391       0.017
2  J102410.04+062943.6    18.163       0.023
3  J102404.63+062938.7    18.962       0.025

The known star X5 is ~0.5m brighter than assumed R mag from SDSS DR9, 
i.e. R = 20.24 +/- 0.06, in accordance with Singer et al. (GCN 15878).
We also may suspect, that known galaxy G5 might be brighter in our 
second epoch (Feb. 27) than on first epoch (Feb. 22). We encourage 
further observation of the galaxy G5 to confirm re-brightening, and if 
so the galaxy might be a host of GRB 140219A.

Also we report a redshift of G5 galaxy z= 0.12 +/- 0.12 obtained 
photometrically using SDSS DR9 catalog.