Title: SN 2013ab : A normal type IIP supernova in NGC 5669 Author: Subhash Bose, Stefano Valenti, Kuntal Misra, Maria Letizia Pumo, Luca Zampieri, David Sand, Brijesh Kumar, Andrea Pastorello, Firoza Sutaria, Thomas J. Maccarone, Brajesh Kumar, M. L. Graham, D. Andy Howell, Paolo Ochner, H. C. Chandola, Shashi B. Pandey
We present densely-sampled ultraviolet/optical photometric and low-resolution optical spectroscopic observations of the type IIP supernova 2013ab in the nearby (~24 Mpc) galaxy NGC 5669, from 2 to 190d after explosion. Continuous photometric observations, with the cadence of typically a day to one week, were acquired with the 1-2m class telescopes in the LCOGT network, ARIES telescopes in India and various other telescopes around the globe. The light curve and spectra suggest that the SN is a normal type IIP event with a plateau duration of ~80 days with mid plateau absolute visual magnitude of -16.7, although with a steeper decline during the plateau (0.92 mag 100 d-1 in V band) relative to other archetypal SNe of similar brightness. The velocity profile of SN 2013ab shows striking resemblance with those of SNe 1999em and 2012aw. Following the Rabinak & Waxman (2011) prescription, the initial temperature evolution of the SN emission allows us to estimate the progenitor radius to be ~ 800 solar radii, indicating that the SN originated from a red supergiant star. The distance to the SN host galaxy is estimated to be 24.3 Mpc from expanding photosphere method (EPM). From our observations, we estimate that 0.064 solar masses of 56Ni was synthesised in the explosion. General relativistic, radiation hydrodynamical modelling of the SN infers an explosion energy of 0.35 x 1051 erg, a progenitor mass (at the time of explosion) of ~9 solar masses and an initial radius of ~600 solar radii.