TITLE: GCN CIRCULAR NUMBER: 27067 SUBJECT: LIGO/Virgo S200213t: No Counterparts from GECKO observation of host galaxy candidates in GW-neutrino detection overlap area DATE: 20/02/14 10:32:59 GMT FROM: Gregory SungHak Paek at SNU Gregory S.H. Paek (SNU), Myungshin Im (SNU), Hyun-Il Sung (KASI), Gu Lim (SNU), Joonho Kim (SNU), Sungyong Hwang (SNU), Bomi Park (SNU), Sophia Kim (SNU), Changsu Choi (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Hyung Mok Lee (KASI), on behalf of GECKO team We observed 4 host galaxy candidates with the 1.0-m telescope at the Lemonsan Optical Astronomical Observatory(LOAO) in the initial localization area of S200213t (Singer et al, GCN #27042) overlapped with neutrino detection area (Hussain et al, GCN #27043). The observation started at 2020-02-14 02:37:28 UT, 0.94 days after GW trigger and each image was taken in R-band with 30 minutes exposure time. No obvious transient has been identified. The list of the inspected targets is given below. NAME DISTANCE[Mpc] DATE-OBS FILTER UL[AB] ---------------------- ------------- ----------------------- ------ ------- PGC11312 169 2020-02-14T02:37:28.000 R 21.676 2MASS+03012583+3135093 254 2020-02-14T03:15:37.333 R 21.626 UGC02483 92 2020-02-14T04:04:08.933 R 21.511 2MASS+03014097+3153413 97 2020-02-14T04:43:56.667 R 21.163 We thank the LOAO opertator 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.