TITLE:   GCN CIRCULAR
NUMBER:  20793
SUBJECT: LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
DATE:    17/03/02 13:53:53 GMT
FROM:    Chao Wu at NAOC  <wuchao.lamost@gmail.com>

J.Y. Wei (NAOC), C. WU (NAOC), J. Wang (NAOC), N. Leroy (LAL),
S. Antier (LAL), X.H. Han (NAOC), L.P. Xin (NAOC), X.M. Meng (NAOC),
L. Huang (NAOC), Y. Xu (NAOC), H.B. Cai (NAOC), X.M. Lu (NAOC),
Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Cao (NAOC), S. Wang (NAOC),
L. Jia (NAOC), S.C. Zou (NAOC), S.F. Liu (NAOC), Q.C. Feng (NAOC),
H.L. Li (NAOC), D.W. Xu (NAOC), Y.J. Xiao (NAOC), W.L. Dong (NAOC),
Y.T. Zheng (NAOC), E.W.Liang (GXU), X.G.Wang (GXU), Y.G. Yang (HBNU),
B. Cordier (CEA), S.N. Zhang (NAOC), D. Dornic (CPPM), B.B. Wu (IHEP),
J.L. Atteia (IRAP), D. Götz (CEA), C.Lachaud (APC),
on behalf of the SVOM Gravitational Astronomy group report:

We observed about 2000 square degree (5 sky regions) of the skymap
of the advanced LIGO trigger G275697, with SVOM/Mini-GWAC, at Xinglong
Observatory of NAOC equipped with U9000 camera (FOV~400 square
degree/camera).
SVOM/Mini-GWAC comprises 12 wide field angle cameras (aperture=7cm),
working with unfiltered band. The observations are operated in time-series
mode, taking one exposure in 15 seconds (10s exposure + 5s readout).
The limit magnitude is ~12 mag in R band. We estimate a 7.44% prior
probability that these 5 regions contain the true location of the
source.

The coordinates of the 5 regions and observation time are list following:

start-obs(UTC)  end-obs(UTC)    Ra      Dec     Camera_ID
2017-03-01      10:55:43.4      2017-03-01      18:11:04.6      09:10:04.5
     +29:30:47                       C1
2017-03-01      10:55:26.9      2017-03-01      14:04:55.7      03:52:34.0
     +68:53:23                       C3
2017-03-01      10:55:26.9      2017-03-01      14:04:55.7      04:02:12.2
     +48:48:08                       C4
2017-03-01      10:55:24.5      2017-03-01      17:44:07.8      06:34:55.5
     +69:32:01                       C5
2017-03-01      10:55:24.5      2017-03-01      17:44:07.8      06:40:15.5
     +50:32:35                       C6

The first image was taken ~2 days 16 hours after the event trigger
due to bad wheather condition. No any significant transient is
found in our online pipeline. The image analysis is ongoing in
detailed processing with our offline pipeline.