Type II-P supernovae as standardized candles: Improvements using near-infrared data

We present the first near-infrared Hubble diagram for Type II-P supernovae (SNe), to further explore their value as distance indicators. We use a modified version of the standardized candle method, which relies on the tight correlation between the absolute magnitudes of Type II-P SNe and their expansion velocities during the plateau phase. Although our sample contains only 12 II-P SNe and they are necessarily local (z < 0.02), we demonstrate using near-infrared JHK photometry that it may be possible to reduce the scatter in the Hubble diagram to 0.1-0.15 mag. While this is potentially similar to the dispersion seen for Type Ia SNe, we caution that this needs to be confirmed with a larger sample of II-P SNe in the Hubble flow. © 2010 The Authors. Journal compilation © 2010 RAS