TITLE: GCN CIRCULAR NUMBER: 21531 SUBJECT: LIGO/Virgo G298048: DLT40 optical candidate DATE: 17/08/18 01:41:13 GMT FROM: Stefano Valenti at UC Davis Sheng Yang (INAF-OAPd, UC Davis), Stefano Valenti(UC Davis), David Sand (UA), Leonardo Tartaglia (UA, UC Davis), Enrico Cappellaro(INAF-OAPd), Dan Reichart, Josh Haislip Vladimir Kouprianov (UNC) We report the discovery of DLT17ck. The object was discovered on 2017-08-17.99 UT at R~17.3 mag, during the ongoing D<40 Mpc (DLT40) one day cadence supernova search, using data from the PROMPT 5 0.41m telescope located at CTIO. A confirmation image was obtained on 2017-08-18.02 UT with the PROMPT telescope. DLT17ck is located at RA: 13:09:48.09 Dec: -23:22:53.4.6, 5.37 W, 8.60 S arcsec offset from the center of the host galaxy, NGC 4993, consistent with the source found by Coulter et al. (LVC GCN 21529).