TITLE: GCN CIRCULAR NUMBER: 25136 SUBJECT: LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations DATE: 19/07/21 14:01:38 GMT FROM: Bin Li at PMO Bin Li, Hai-bin Zhao (PMO),Dong Xu, Zi-pei Zhu, Bang-Yao Yu,Tian-meng Zhang, Xu Zhou,Chen-zhou Cui, Hui-juan Wang(NAOC), Xue-feng Wu, Zhi-ping Jin, Tian-rui Sun, Hao Lu, Ge-tu Zhaori, Ren-quan Hong, Long-fei Hu (PMO), Xiao-feng Wang, Wen-xiong Li (THU),Li-fan Wang (PMO/TAMU), Jin-zhong Liu (XAO), Ji-rong Mao, Jin-ming Bai (YNAO), report on behalf of the CNEOST collaboration. We conducted optical imaging observations for gravitational wave alert with Chinese Near Earth Object Survey Telescope (CNEOST) at Xuyi astronomical station in Jiangsu Province, China (32.75N, 118.47E). The information of observations and preliminary results are listed below. Alert: LIGO/Virgo S190720a (GCN #25115) StartTime (UT): 2019-07-20T13:52:48.017 EndTime (UT): 2019-07-20T14:48:48.031 Skycover (Square Degree): 135.0 Telescope FoV (Square Degree):9.0 #id CentRA(D) CentDEC(D) LimiteMag3_sig 5_sig 10_sig Filter 1 231.208405 43.572357 - 21.204 18.323 SR 2 242.761490 46.336327 21.949 21.134 18.424 SR 3 242.799225 43.565426 22.074 21.229 18.375 SR 4 228.608490 40.790733 - 21.204 18.483 SR 5 221.265320 40.808392 21.856 21.045 18.350 SR 6 231.208405 43.572357 - 21.204 18.323 SR 7 242.761490 46.336327 21.949 21.134 18.424 SR 8 242.799225 43.565426 22.074 21.229 18.375 SR 9 228.608490 40.790733 - 21.204 18.483 SR 10 221.265320 40.808392 21.856 21.045 18.350 SR 11 231.208405 43.572357 - 21.204 18.323 SR 12 242.761490 46.336327 21.949 21.134 18.424 SR 13 242.799225 43.565426 22.074 21.229 18.375 SR 14 228.608490 40.790733 - 21.204 18.483 SR 15 221.265320 40.808392 21.856 21.045 18.350 SR The new resulte will available at http://www.cneost.org/opem/list.php?gdate=2019-07-20