TITLE: GCN CIRCULAR NUMBER: 18850 SUBJECT: LIGO/Virgo G211117: Distance estimate from GW data compared to redshift of PS15dpn DATE: 16/01/10 14:56:55 GMT FROM: Peter Shawhan at U of Maryland/LSC The LIGO Scientific Collaboration and Virgo report: We have performed a parameter estimation analysis assuming that G211117 is a binary coalescence event with (RA,Dec) constrained to be the position of PS15dpn (Smith et al., GCN 18786; Chambers et al., GCN 18811) and allowing for calibration uncertainties in the LIGO detectors. Our preliminary analysis finds a posterior probability distribution for redshift with a central 90% credible interval of 0.07 to 0.13. There is almost no support for a source at the redshift reported for PS15dpn, z=0.175 (GCN 18811; also Cenko et al., GCN 18848, measured z=0.174), although it is not entirely ruled out.