Do the photometric colors of Type II-P Supernovae allow accurate determination of host galaxy extinction?

TL;DR

This study investigates whether photometric colors of Type II-P supernovae can reliably determine host galaxy extinction, using detailed observations of two supernovae and comparing their extinction and luminosity.

Contribution

It demonstrates a method to estimate supernova host galaxy extinction using color curves and compares the absolute magnitudes of different supernova types.

Findings

Color curves of SNe II-P are similar during plateau phase

Host galaxy extinction can be estimated from color evolution

Comparison of supernova magnitudes informs about extinction effects

Abstract

We present infrared photometry of SN 1999em, plus optical photometry, infrared photometry, and optical spectroscopy of SN 2003hn. Both objects were Type II-P supernovae. The V-[RIJHK] color curves of these supernovae evolved in a very similar fashion until the end of plateau phase. This allows us to determine how much more extinction the light of SN 2003hn suffered compared to SN 1999em. Since we have an estimate of the total extinction suffered by SN 1999em from model fits of ground-based and space-based spectra as well as photometry of SN 1999em, we can estimate the total extinction and absolute magnitudes of SN 2003hn with reasonable accuracy. Since the host galaxy of SN 2003hn also produced the Type Ia SN 2001el, we can directly compare the absolute magnitudes of these two SNe of different types.