Difference: GCNCIRCULAR20781 ( vs. 1)

B. Li, H.B. Zhao (PMO/CAS), D. Xu (NAO/CAS), G.T. Zhaori, H. Lu, R.Q. Hong, L.F. Hu (PMO/CAS), T.M. Zhang, X. Zhou, H.X. Feng, Z.P. Zhu (NAO/CAS), J.Z. Liu, H.B. Niu, Y. Zhang, X. Zhang, G.X. Pu, S.G. Ma,T.Z. Yang, F.F. Song (XAO/CAS), J. Mao, J.M. Bai (YNAO/CAS) report on behalf of the GWFUNC collaboration:

We have performed tiled observations of LIGO/Virgo G275697 (LVC, GCN 20763) using the 1-m Chinese Near Earth Object Survey Telescope (CNEOST) at Xuyi, Jiangsu, China.

CNEOST carried out observations during 11:29:44.6 UT - 14:51:15.1 UT on 2017-02-28 in the Sloan r-filter. The imaging coverage on top of the GW probability map is at

https://dl.dropboxusercontent.com/u/3665676/G275697/skymapG275697CNEOST.pdf

and the limiting magnitude varied from m(r)~16 to ~20 mag due to weather variation.

Preliminary analysis doesn't reveal credible optical transients except supernovae discovered prior to the G275697 trigger time.

-- ThomasKupfer - 01 Mar 2017