TITLE: GCN CIRCULAR NUMBER: 18807 SUBJECT: LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates DATE: 16/01/02 18:50:49 GMT FROM: Chris Copperwheat at LJMU ArI We report the following spectroscopic observations and classifications of a number of the EM candidates reported by Cenko et al. in GCN 18762. All observations were obtained using the 2.0 metre Liverpool Telescope, La Palma by C.M. Copperwheat & I.A. Steele (Liverpool JMU) on behalf of a wider collaboration. iPTF-15fhp was observed with the SPRAT spectrograph on 2016-01-01 at 00:58UT. The spectrum was of quite poor quality and SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) provides a tentative classification of a type Ia supernova approximately one week before peak. We have scheduled a second observation to test this classification. iPTF-15ffz was observed with the SPRAT spectrograph on 2016-01-01 at 19:26UT. A number of emission lines are observed: including OII, H-beta and H-alpha with a common redshift of 0.070. This is consistent with the SDSS photometric redshift of the proposed host galaxy (z=0.075). We believe this target to be an AGN. iPTF-15fed was observed with the SPRAT spectrograph on 2016-01-01 at 20:03UT. We do not see a point source distinct from the galactic emission in our acquisition image, however we estimate the limiting magnitude of this image is R~19.1, compared to the transient magnitude of 19.9 reported by iPTF. The spectrum we obtain is dominated by emission from the host galaxy. iPTF-15fib was observed with the SPRAT spectrograph on 2016-01-01 at 20:39UT. We do not detect an object at those coordinates in our acquisition image. We estimate the limiting magnitude of this image is R~19.5, which is the same as the transient magnitude reported by iPTF. The spectrum we obtained was blank. Possibly this object has faded. iPTF-15ffk was observed with the SPRAT spectrograph on 2016-01-01 at 21:16UT. Classification using SNID indicates the transient is a type Ia supernova with z = 0.108 -/+ 0.005 at 6.9 days past peak. This redshift is consistent with the SDSS photometric redshift of the proposed host galaxy (z=0.11). iPTF-15fgy was observed with the SPRAT spectrograph on 2016-01-01 at 21:55UT. Classification using SNID indicates the transient is a type Ia supernova with z = 0.072 -/+ 0.006 at 16.8 days past peak.