[vsnet-grb-info 5524] XRF 080109 / SN 2008D: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7187
SUBJECT: XRF 080109 / SN 2008D: optical observations
DATE:    08/01/16 01:23:04 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Pavlenko, A. Litvinchova, Yu. Efimov (CrAO),   A. Pozanenko (IKI) report
on behalf of a larger collaboration:

We observed the optical transient of XRF 080109/SN 2008D in NGC 2770
(Berger,  Soderberg, GCN 7159; Deng, Zhu, GCN 7160) on January 11,12,13 with
CrAO 2.6 telescope  (ZTSh).  On Jan. 11 observations were completed in BVRI
and on Jan. 12-13 in BR filters under good weather conditions.

Preliminary photometry of the transient XRF 080109/SN 2008D obtained after
galaxy subtracion and assuming  reference stars from USNO-A2.0
1200-06240802,  R=17.3, B=17.7 (the same star used in GCN 7162 (D'Elia et
al)):

Mid time (UT), Filter, magnutude

Jan. 12.04 B 18.63
Jan. 12.04 R 17.98
Jan. 13.01 B 18.74
Jan. 12.99 R 18.04
Jan. 13.93 B 18.84
Jan. 14.01 R 17.98

Typical statistical uncertainties of magnitude in the table above is better
than 0.01.  Magnitudes are not corrected for Galaxy reddening.

Within our observations  B magnitude is fading  on Jan. 11-13, while the R
brightness has a minimum on the night on Jan. 12/13.  Color (B-R) gradually
increasing from 0.65 (Jan. 12) to 0.86 (Jan. 14) which aslo may support of
SN dominance in light  curve of the transient (Malesani et al. GCN 7184).