Optical/NIR light curves of SN 2009ib

We also apply EPM to SN 1986L, a Type II-P SN that exploded in the same galaxy. Combining the results of different methods, we conclude the distance to NGC 1559 as D=19.8+/-3.0Mpc. We examine archival, pre-explosion images of the field taken with the Hubble Space Telescope, and find a faint source at the position of the SN, which has a yellow colour [(V-I)_0_=0.85mag].

Assuming it is a single star, we estimate its initial mass as M_ZAMS_=20M_{sun}_. We also examine the possibility, that instead of the yellow source the progenitor of SN 2009ib is a red supergiant star too faint to be detected. In this case, we estimate the upper limit for the initial zero-age main sequence (ZAMS) mass of the progenitor to be ~14-17M_{sun}_.

In addition, we infer the physical properties of the progenitor at the explosion via hydrodynamical modelling of the observables, and estimate the total energy as ~0.55x10^51^erg, the pre-explosion radius as ~400R_{sun}_, and the ejected envelope mass as ~15M_{sun}_, which implies that the mass of the progenitor before explosion was ~16.5-17M_{sun}_.