TITLE: GCN CIRCULAR NUMBER: 21510 SUBJECT: LIGO/Virgo G298048: correction to the luminosity distance reported in GCN 21509 DATE: 17/08/17 14:38:46 GMT FROM: Leo Singer at NASA/GSFC The LIGO Scientific Collaboration and the Virgo Collaboration report: In GCN 21509, we reported the identification of a binary neutron star candidate. We had stated that actual luminosity distance to the source is likely larger than the estimated effective distance. The effective distance quoted estimates the *maximum* distance to the source and so the actual luminosity distance is can be *smaller* than the estimate of the effective distance. The BAYESTAR localization generated from H1 data only estimates an actual luminosity distance of 37 +/- 12 Mpc (a posteriori mean +/- standard deviation). The distance estimate will likely evolve with further offline follow-up using data from H1, L1, and V1. Analyses including data from H1, L1, and V1 are still ongoing and a sky-map using gravitational-wave data will be made available as quickly as possible. [GCN OPS NOTE(17aug17): Per author's request, the LIGO/VIRGO ID was added to the beginning of the Subject-line.]