The Early Detection and Follow-up of the Highly Obscured Type II Supernova 2016ija/DLT16am

Abstract

<p>We present our analysis of the Type II supernova DLT16am (SN 2016ija). The object was discovered during the ongoing D< 40 {Mpc} (DLT40) one-day cadence supernova search at r∼ 20.1 {mag} in the “edge-on” nearby (D=20.0+/- 4.0 {Mpc}) galaxy NGC 1532. The subsequent prompt and high-cadenced spectroscopic and photometric follow-up revealed a highly extinguished transient, with E(B-V)=1.95+/- 0.15 {mag}, consistent with a standard extinction law with R _V = 3.1 and a bright ({M}_V=-18.48+/- 0.77 {mag}) absolute peak magnitude. A comparison of the photometric features with those of large samples of SNe II reveals a fast rise for the derived luminosity and a relatively short plateau phase, with a slope of {S}_50V=0.84+/- 0.04 {mag}/50 {days}, consistent with the photometric properties typical of those of fast-declining SNe II. Despite the large uncertainties on the distance and the extinction in the direction of DLT16am, the measured photospheric expansion velocity and the derived absolute V-band magnitude at ∼ 50 {days} after the explosion match the existing luminosity–velocity relation for SNe II.</p>