Young Stellar Population of the Bright-Rimmed Clouds BRC 5, BRC 7 and BRC 39

TL;DR

This study investigates the young stellar populations in three bright-rimmed clouds, revealing patterns consistent with sequential star formation triggered by radiation-driven implosion, and identifies potential sites of future star formation.

Contribution

It provides a detailed census of young stars in BRC 5, BRC 7, and BRC 39, supporting the radiation-driven implosion model of triggered star formation.

Findings

Younger stars are located near the bright rims of BRCs.

Older stars are found outside the clouds, indicating sequential formation.

Intermediate/high mass stars at the heads may trigger further star formation.

Abstract

Bright-rimmed clouds (BRCs), illuminated and shaped by nearby OB stars, are potential sites of recent/ongoing star formation. Here we present an optical and infrared photometric study of three BRCs: BRC 5, BRC 7 and BRC 39 to obtain a census of the young stellar population, thereby inferring the star formation scenario, in these regions. In each BRC, the Class I sources are found to be located mostly near the bright rim or inside the cloud, whereas the Class II sources are preferentially outside, with younger sources closer to the rim. This provides strong support to sequential star formation triggered by radiation driven implosion due to the UV radiation. Moreover, each BRC contains a small group of young stars being revealed at its head, as the next-generation stars. In particular, the young stars at the heads of BRC 5 and BRC 7 are found to be intermediate/high mass stars, which, under proper conditions, may themselves trigger further star birth, thereby propagating star formation out to long distances.