Debris Disks around Solar-Type Stars: Observations of the Pleiades with Spitzer Space Telescope

TL;DR

This study uses Spitzer observations to analyze debris disks around 71 solar-type stars in the Pleiades, finding that about one-third exhibit infrared excesses indicative of debris disks, with implications for stellar binarity and activity.

Contribution

First comprehensive survey of debris disks around solar-type stars in the Pleiades using Spitzer, comparing incidence rates with other stellar types and clusters.

Findings

Approximately 32% of stars have infrared excesses at 24 um.

Debris disk occurrence around solar-type stars is similar to that around A stars at 115 Myr.

Warm excesses are less common in equal-mass binary systems.

Abstract

We present Spitzer MIPS observations at 24 um of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32 +/- 6.8%, have excesses at 24 um at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak.