TITLE: GCN CIRCULAR NUMBER: 25395 SUBJECT: LIGO/Virgo S190814bv: Keck/MOSFIRE NIR spectroscopy of DG19njmjc (= AT 2019nra) DATE: 19/08/18 20:17:48 GMT FROM: Georgios Dimitriadis at UCSC G. Dimitriadis, J. S. Brown, M. R. Seibert, R. J. Foley, D. A. Coulter, C. D. Kilpatrick, K. Siellez, C. Rojas-Bravo (UCSC) Report on behalf of the 1M2H and the UC-NASA-Keck collaborations: We obtained near-IR spectroscopy of DG19njmjc (= AT 2019nra), a transient spatially coincident with the localization of S190814bv (GCN #25324, GCN #25333), being approximately on the 55th percentile confidence contour, with the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck I telescope on Maunakea, starting at UT 2019-08-18 14:24:52, aproximately 3.7 days after the LIGO/Virgo alert. Our spectrum covers the J-band (1.15-1.35 microns). The spectrum has relatively low S/N (S/N ~ 10), and appears featureless, with no obvious emission or absorption features. We thank the staff of Keck observatory, especially Carlos Alvarez, Randy Campbell, Jim Lyke, Alan Hatakeyama and John O'Meara, for facilitating this Target of Opportunity observation.