UV, optical and near-IR observations of Type II-peculiar SN2018hna in the metal-poor galaxy UGC7534
ATel #12897; J. Rho (SETI Institute), M. Shahbandeh, E. Hsiao, S. Davis (FSU), P. Brown (Texas A&M), S. Valenti, K. A. Bostroem (UC Davis), D. Hiramatsu, J. Burke, D. A. Howell, C. McCully (LCO), T. Szalai, Z. Vinko (U. of Szeged, Hungary) D. P. K. Banerjee (Physical Research Lab., Ahmedabad, India), T. R. Geballe (Gemini Observatory), L. Dessart (CNRS, Universidad de Chile), A. Evans (Keele U., UK), L. Galbany (U. de Granada, Spain) and Global Supernova Project Team.
on 29 Jun 2019; 00:12 UT
Credential Certification: Jeonghee Rho (jrho@seti.org)
Subjects: Infra-Red, Optical, Ultra-Violet, Supernovae
We report UV, optical and near-IR observations of supernova SN 2018hna in UGC7534, a faint and metal-poor galaxy, using SWIFT, the Las Cumbres Observatory (LCO) network and IRTF/SPEX. SN2018hna was discovered on 2018 10-22 by K. Itagaki (TNS #30529). It was reported that the optical light curves have a long rise up to day 35 (ATel #12258). Our light curves show that SN 2018hna has a long rise time of 90 days both in the optical and UV, similar to those of SN1987A. SWIFT UV light curves reveal a rapid drop in flux at early times, which is consistent with the adiabatic cooling after shock breakout. The LCO optical spectra include bright H alpha, H beta, H gamma and Ca lines with the hydrogen lines showing P-Cygni line profiles with broad high-velocity components (~9000 km/s on day 42). Based on the long-rise light curves and hydrogen lines, we classify SN2018hna as Type II-peculiar, making it one of the closest (10.5 Mpc) SNe of this type. Near-IR spectra detect first overtone CO emission at 2.3 microns on days ~153, 171 and 201. The CO mass on day 153 is estimated to be ~0.0002 Msun with a velocity of 3500+-500 km/s and a temperature of 3500+-500 K by using an LTE model. The CO detection may indicate the forthcoming onset of dust formation in the SN ejecta.
