Spectral class distribution of circumstellar material in main-sequence stars

A detailed statistical evaluation of IRAS survey data of main-sequence stars within 25 pc indicates that the presence of cool shells around A, F, and G main-sequence stars is the rule, rather than the exception. While luminosity bias favors A and F stars, the typical G star still appears to have almost three orders of magnitude more excess than the excess of the solar system due to known zodiacal dust and all planets combined. The Vega effect is thus not restricted to stars of particularly young age. The finding that the 'archetypical' solar system appears to have much less far-IR excess than the majority of G stars supports a speculation that the sun could have a cloud of cold particles beyond the outer planets, undetected by IRAS viewing from earth.