Identifying Nearby, Young, Late-type Stars by Means of Their Circumstellar Disks

TL;DR

This study demonstrates that mid-infrared excess emission detection effectively identifies nearby, young, late-type stars with circumstellar disks, leading to discovery of new members in young stellar associations.

Contribution

The paper introduces a method using mid-IR excess emission to find young, late-type stars and reports new members of the TW Hydrae Association and evidence of disks around other young stars.

Findings

Identified two new TWA members with mid-IR excess.

Detected circumstellar disk around a young star in Scorpius-Centaurus.

Validated mid-IR excess as a reliable indicator of youth and disks.

Abstract

It has recently been shown that a significant fraction of late-type members of nearby, very young associations (age <10 Myr) display excess emission at mid-IR wavelengths indicative of dusty circumstellar disks. We demonstrate that the detection of mid-IR excess emission can be utilized to identify new nearby, young, late-type stars including two definite new members ("TWA 33" and "TWA 34") of the TW Hydrae Association. Both new TWA members display mid-IR excess emission in the Wide-field Infrared Survey Explorer (WISE) catalog and they show proper motion and youthful spectroscopic characteristics -- namely H\alpha emission, strong lithium absorption, and low surface gravity features consistent with known TWA members. We also detect mid-IR excess -- the first unambiguous evidence of a dusty circumstellar disk -- around a previously identified UV-bright, young, accreting star (2M1337) that is a likely member of the Lower-Centaurus Crux region of the Scorpius Centaurus Complex.