M-Type Vega-like Stars

Abstract

We carried out a search for M-type Vega-like stars by correlating the IRAS Faint Source Catalog with Hipparcos-selected M-type stars. Three stars with apparent IRAS 25 μm excess emission are shown instead to be non-IR-excess stars from ground-based 11.7 and 17.9 μm photometry. Two stars previously suggested to have Vega-like mid-IR excess are also shown to be nonexcess stars. These results imply that other suggested mid-IR-excess stars in the literature may also be false excess stars. Detection threshold bias is apparently responsible for these bogus IR excesses. Sixty micron excess emission from a previously known M-type Vega-like star (GJ 803) is identified again.