Difference: GCNCIRCULAR21755 ( vs. 1)

C.M.Copperwheat (LJMU) and I.A.Steele (LJMU) report on behalf of

D.Bersier (LJMU), M.Bode (LJMU), C.Collins (LJMU), M.Darnley (LJMU), D.Galloway (Monash), A.Gomboc (Nova Gorica), S.Kobayashi (LJMU), A. Levan (Warwick), P.Mazzali (LJMU), C.Mundell (Bath), D.Perley (LJMU), E.Pian (Pisa), A.S. Piascik (LJMU), D. Pollacco (Warwick), D. Steeghs (Warwick), N.Tanvir (Leicester), K. Ulaczyk (Warwick), K.Wiersema (Leicester)

and the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration.

We observed MASTER OTJ033744.97+723159.0, originally reported in GCN #21720, on 2017-08-29 at 04:05UT using the SPRAT spectrograph on the Liverpool Telescope. We concur with the classification reported in GCN #21737: using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) with the redshift of NGC1343 we believe this transient to be a supernova Type IIb at 2 days before maximum.

We also observed the field of the optical transient discovered with Swift/UVOT (GCN #21733) in ugriz with the IO:O imager on the Liverpool Telescope, starting at 03:31UT on 2017-08-29. We do not detect an object at these coordinates, as has already been reported by a number of different groups. Our magnitude limits are comparable to those obtained with the Asiago 1.82 m Copernico Telescope (GCN #21745).

-- ThomasKupfer - 29 Aug 2017