[vsnet-grb-info 20352] GRB 180224A: AbAO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22448
SUBJECT: GRB 180224A: AbAO optical observations
DATE:    18/02/25 20:06:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI),  A. Pozanenko (IKI),  A. Volnova  (IKI), R. Inasaridze 
(AbAO),  V. Ayvazian  (AbAO),  O. Kvaratskhelia (AbAO), G. Inasaridze 
(AbAO),  I. Molotov (KIAM), report on behalf of larger GRB follow-up 
collaboration:

We observed the field of GRB 180224A  (Lien  et al., GCN 22442) with AS-32 
(0.7m) telescope of Abastumani Observatory starting on Feb. 25  (UT) 
01:07:37.   The afterglow of GRB 180224A (Lien  et al., GCN 22442; 
Vladimirov et al., GCN 22444) is  clearly detected in a stacked image. 
Preliminary photometry is following.

Date              UT start      t-T0         Filter   Exp.    OT       Err. 
UL
                      (mid, days)                            (s)

2018-02-25  01:07:37   0.15162   CR     60*60  21.88   0.15  22.6

The photometry is based on nearby SDSS DR9 stars

SDSS_id                            R_Lupton
J133038.17+380528.6    17.45
J133040.16+380535.7    17.10
J133051.85+380146.4    17.91

We confirm the fast decay of the afterglow and possible host galaxy 
association  SDSS DR9 J133044.06+380443.0 with the afterglow source (Watson 
et al., GCN 22446).