TITLE: GCN CIRCULAR NUMBER: 27258 SUBJECT: SUBJECT : LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates DATE: 20/02/28 14:42:34 GMT FROM: Gu Lim at Seoul National U SUBJECT : LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates Gu Lim (SNU), Myungshin Im (SNU), Gregory S.H. Paek (SNU), Joonho Kim (SNU), Sungyong Hwang (SNU), Bomi Park (SNU), Sophia Kim (SNU), Changsu Choi (SNU), Shuhrat A. Ehgamberdiev (UBAI), Otabek Burkhonov (UBAI), Davron Mirzaqulov (UBAI), Hyung Mok Lee (KASI), on behalf of GECKO team We performed follow-up observation for host galaxy candidates (Paek et al. GCN #27067, GCN #27119) continuously using AZT-22 1.5m telescope at Maidanak Astronomical Observatory in Uzbekistan in the initial and updated localiztion area of S200213t (Singer et al, GCN #27042) and overlapped neutrino detection area (Hussain et al, GCN #27043). No significant EM counterpart candidates were found in the stacked images. Single images were taken in B and R-band of 180 or 300 seconds. Observation results are listed below. DEPTH is 5-sigma detection limit for point source in AB magnitude. Flux calibration is conducted using APASS DR9 catalog. NAME RA[J2000] DEC[J2000] DISTANCE[Mpc] DATE-OBS [UT] FILTER EXPTIME[s] DEPTH[AB] ================================================================================================================================ PGC11312 02:59:27.180 +31:23:09.161 169 2020-02-14T14:33:57 B 1500 23.35 PGC11312 02:59:27.180 +31:23:09.161 169 2020-02-20T14:33:12 B 900 23.05 PGC11312 02:59:27.180 +31:23:09.161 169 2020-02-14T15:01:51 R 1500 22.08 PGC11312 02:59:27.180 +31:23:09.161 169 2020-02-20T14:50:37 R 900 22.64 UGC02483 03:01:36.753 +31:49:09.293 91 2020-02-14T16:33:02 B 600 18.42 UGC02483 03:01:36.753 +31:49:09.293 91 2020-02-20T15:53:40 B 900 22.29 UGC02483 03:01:36.753 +31:49:09.293 91 2020-02-20T16:11:05 R 900 21.84 2MASS+03014097+3153413 03:01:40.977 +31:53:41.330 97 2020-02-20T16:34:54 B 900 22.72 2MASS+03014097+3153413 03:01:40.977 +31:53:41.330 97 2020-02-20T16:52:18 R 900 22.00 2MASS+03012583+3135093 03:01:25.837 +31:35:09.301 254 2020-02-14T15:39:28 B 1500 23.40 2MASS+03012583+3135093 03:01:25.837 +31:35:09.301 254 2020-02-20T15:13:47 B 900 23.18 2MASS+03012583+3135093 03:01:25.837 +31:35:09.301 254 2020-02-14T16:06:57 R 1500 22.88 We thank all staff in Maidanak observatory for performing the observation. Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network of 10+ 0.5m to 1m class telescopes over the world. ���