[vsnet-grb-info 18558] GRB 160925A: Kottamia R-band observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20006
SUBJECT: GRB 160925A: Kottamia R-band observation
DATE:    16/10/06 23:05:13 GMT
FROM:    Gamal B. Ali at NRIAG  <gamalali at lycos.com>

FROM:    G. B. Ali at NRIAG  <gamalali at lycos.com>

report on behalf of the Kottamia collaboration:

G. B. Ali, Y. Hendy, A. Takey, N. Essam, and A. Essam (NRIAG, Egypt) 

We observed the field of the Fermi GRB 160925A (trigger #496473540) with
the 1.88m telescope of the KAO (Kottamia Astronomical Observatory),
Egypt. The observation was performed in the Rc-band at the Newtonian
camera (F4.8) and started at 2016-09-29 T19:58:17 UT (~4.08 day after
the burst). 

We obtained several exposures in the Rc-band each one with 300s exposure
time.  We clearly detected the optical transient (Lipunov et al., GCN
19938; Guidorzi et al., GCN  19939). 

The following accurate photometry is obtained for the transient: 

UT (Start)                            Rc           error*   

2016-09-29T19:58:17       17.260   0.011 

2016-09-29T20:03:31       17.232   0.011 

2016-09-29T20:08:42       17.252   0.012 

2016-09-29T20:13:53       17.326   0.013 

2016-09-29T20:19:04       17.267   0.012 

2016-09-29T20:24:15       17.223   0.011 

2016-09-29T20:29:26       17.305   0.011 

2016-09-29T20:34:37       17.281   0.012 

2016-09-29T20:39:48       17.239   0.011 

---------------------------------------------------- 

(*) Poisson noise error only. 

The Photometric calibration is based on nearby USNO-B1.0 stars

USNO-B1.0        R2 

0750-0813981 13.69 

0750-0813991 14.20 

0750-0813958 14.93 

0750-0813917 15.62

---
With my best regards.
Yours,
Gamal
--
===================
Gamal B. Ali, PhD
Astronomy Dept.
National Research Institute of Astronomy and Geophysics
11421 - Helwan, Cairo, Egypt
Tel: +20 2 255-60645
Fax: +20 2 255-48020
Mobile: +20 1008818634
=================== 
On 2016-09-27 14:45, GCN Circulars wrote:

> TITLE:   GCN CIRCULAR
> NUMBER:  19947
> SUBJECT: GRB 160925A/MASTER optical transient: Mondy optical observations
> DATE:    16/09/27 12:34:06 GMT
> FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>
> 
> E. Mazaeva (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova 
> (IKI), I. Korobtsev (ISTP)  report on behalf of larger GRB follow-up 
> collaboration:
> 
> We observed the field of the Fermi GRB 160925A (trigger #496473540) with 
> AZT-33IK telescope of Sayan observatory (Mondy) starting on Sep., 26 
> (UT) 14:38:09. We obtained several images in R-filter. We  clearly 
> detected optical transient (Lipunov et al., GCN 19938; Guidorzi et al., 
> GCN  19939). Preliminary photometry  of the transient is following
> 
> Date        UT start   t-T0      Filter Exp.   OT        UpLim (3 sigma)
> (mid, days)       (s)
> 2016-09-26  14:38:09   0.88014    R      30*120 16.06+/-0.03  23.0
> 
> Photometry is based on nearby USNO-B1.0 stars
> 
> USNO-B1.0 R2
> 0750-0813972 16.86
> 0750-0813954 17.70
> 0750-0813947 17.78