FLOYDS Classification of AT 2018hti / ATLAS18yff as a Young Nearby SLSN-I
ATel #12183; I. Arcavi (Tel Aviv U.), J. Burke, D. Hiramatsu, C. McCully, D. A. Howell (Las Cumbres Obs./UCSB), S. Valenti (UC Davis)
on 7 Nov 2018; 12:33 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Iair Arcavi (arcavi@gmail.com)
Subjects: Optical, Supernovae
We obtained a spectrum of AT 2018hti / ATLAS18yff (Tonry et al. 2018, TNSCR 23913) on 2018 November 6.6 UT with the robotic FLOYDS instrument mounted on the Las Cumbres Observatory 2-meter telescope on Haleakala, Hawai'i, under the Global Supernova Project (PI: Howell).
Using Superfit (Howell et al. 2005, ApJ, 634, 1190), we find a good fit to the SLSN-I PTF09cnd at 16 days before peak. We measure the redshift to be 0.062 from narrow host H and O III lines. Las Cumbres Observatory images taken on 2018 November 4 show a MW-extinction-corrected V-band absolute magnitude of the supernova of -20.7 (this value may include some host-galaxy contamination).
Our spectrum is publicly available on the Transient Name Server. Further followup is encouraged.
