Classification of ASASSN-15ml and ASASSN-15mm

ATel #7802; A. S.Piascik, C. Ashall, I. Steele (LJMU)
on 15 Jul 2015; 09:26 UT
Credential Certification: Chris Ashall (c.ashall@2013.ljmu.ac.uk)

Tweet

ASASSN-15ml We conducted a spectroscopic observation of transient ASASSN-15ml at 2015-07-15T:00:57:50 UT. This transient was reported in ATel #7791 by the All Sky Automated Survey for SuperNovae with a discovery timestamp 2015-07-12.46 UT. A spectrum was obtain in the visible, 400-800nm, with resolution R~350, using the SPRAT spectrograph on the Liverpool Telescope located at Roque de los Muchachos on La Palma. Classification using SNID (Blondin and Tonry 2007, ApJ, 666, 1024) indicates it is a type Ia supernova. We find a close match with SN2005am at +15 days after maximum and an estimated red-shift z=0.020, consistent with that of the proposed host galaxy 2MASX J20030163-2154516, z=0.019. We estimate an expansion velocity from the Si-II (635.5nm) absorption feature of 10,000 km/s. ASASSN-15mm We conducted a two spectroscopic observation of transient ASASSN-15mm. This transient was reported in ATel #7791 by the All Sky Automated Survey for SuperNovae with a discovery timestamp 2015-07-12.46 UT. Our first spectrum taken on 2015-07-13T21:42:00 UT indicated a minor position error in the reported declination and we suggest a revised RA=15:25:23.50 DEC=29:10:26.47 for this transient. A second spectrum was successfully obtained on 2015-07-14T21:28:49 UT with the revised co-ordinate. Spectra were obtain in the visible, 400-800nm, with resolution R~350, using the SPRAT spectrograph on the Liverpool Telescope located at Roque de los Muchachos on La Palma. Classification using SNID (Blondin and Tonry 2007, ApJ, 666, 1024) indicates it is a type II supernova. We find a close match with SN199gi at -5 days pre-maximum and an estimated red-shift, z=0.020, consistent with that of the proposed host galaxy SDSS J152523.40+291018.8, z=0.21.