TITLE: GCN CIRCULAR NUMBER: 24971 SUBJECT: LIGO/Virgo S190701ah: KMTNet Observation DATE: 19/07/03 08:13:50 GMT FROM: Joonho Kim at Seoul National U. Myungshin Im (SNU), Joonho Kim (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Gregory S. H. Paek (SNU), Gu Lim (SNU), Changsu Choi (SNU), Sungyong Hwang (SNU), Sophia Kim (SNU), Bomi Park (SNU), Hyung Mok Lee (KASI), on behalf of a larger collaboration We observed the 70% credible region (~34 deg^2) of the localization map of the BBH merger candidate, S190510g (LIGO/Virgo GCN 24950) with KMTNet at Chile (CTIO) starting at 2019-07-02 09:03:19 UT. The images were taken in R-band with 240 sec exposure time to the depth of R ~ 22 mag (5-sigma detection). The central coordinate of each 2 deg x 2deg pointing is given below. The search for transients is ongoing. target ra dec G331903-0 02:34:29.0 -05:50:16 G331903-1 02:26:10.6 -07:50:16 G331903-2 02:34:14.0 -07:50:16 G331903-3 02:26:27.3 -05:50:16 G331903-4 02:25:32.5 -09:50:16 G331903-5 02:33:38.3 -09:50:16 G331903-6 02:35:21.2 -03:50:16 G331903-7 02:27:20.6 -03:50:16 G331903-8 02:24:59.4 -11:50:16 G331903-9 02:36:13.6 -01:50:16 G331903-10 02:33:08.1 -11:50:16 G331903-11 02:28:13.6 -01:50:16 We thank the KMTNet observers for performing the observation. ���