FLOYDS Classification of ASASSN-15oz as a Young Type II Supernova and ASASSN-15os as a Few-Week-Old Type Ia Supernova
ATel #7997; G. Hosseinzadeh (LCOGT/UCSB), S. Valenti (UC Davis), I. Arcavi, C. McCully, D. A. Howell (LCOGT/UCSB)
on 4 Sep 2015; 23:01 UT
Credential Certification: Iair Arcavi (firstname.lastname@example.org)
Subjects: Optical, Supernovae
We obtained a spectrum of ASASSN-15oz (ATel #7989) on 2015 September 4.5 UT with the robotic FLOYDS instrument mounted on the Faulkes Telescope South. Using SNID (Blondin & Tonry 2007, ApJ, 666, 1024), we find a good fit to the Type II SN 1999gi one week after explosion at the redshift of the proposed host galaxy (z=0.007; Meyer et al. 2004, MNRAS, 350, 1195, via SIMBAD). The underlying continuum is quite blue and the redshift puts the supernova luminosity at the high end of Type II events (absolute mag ~-18). The spectrum also exhibits a relatively strong absorption feature near 620 nm, which has been identified in similar objects as high-velocity H-alpha (Chugai, Chevalier, & Utrobin 2007, ApJ, 662, 1136) or Si II (Valenti et al. 2014, MNRAS, 438, L101). We have requested ultraviolet photometric and spectroscopic follow-up under our Swift GI program (Proposal Number 1114241; PI: Valenti).
We also obtained a spectrum of ASASSN-15os (ATel #7941) on 2015 September 4.6 UT with the robotic FLOYDS instrument mounted on the Faulkes Telescope South. Using SNID (Blondin & Tonry 2007, ApJ, 666, 1024), we find a good fit to the normal Type Ia SN 1998bu 12 days after maximum light at redshift z=0.039.