TITLE: GCN CIRCULAR NUMBER: 24318 SUBJECT: LIGO/Virgo S190425z: No source found at UVOT source location at 6 hrs after LVC report DATE: 19/04/28 03:51:56 GMT FROM: Myungshin Im at Seoul Nat U Myungshin Im (SNU), Joonho Kim (SNU), Gregory S. H. Paek (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Hyung Mok Lee (KASI), on behalf of a larger collaboration We checked the KMTNet image at the location of the UVOT transient (Breeveld et al., GCN Circ. 24296). The image was taken at 2019-04-25 14:05:29 (UT) at the KMTNet Siding Spring Observatory station, about 6 hours after the GW detection (LVC collaboration, GCN Circ. 24168) and 28 hours before the reported UVOT detection. We do not find any transient at the UVOT location down to the preliminary magnitude limit of R<21.5 (3-sigma, point source). We do find the reported faint host galaxy candidate in our KMTNet data (Palmese et al., GCN Circ. 24312) We thank the KMTNet operators for performing the observation.