In-Situ Star Formation in the Outskirts of the Large Magellanic Cloud: Gaia DR2 Confirmation

TL;DR

This study uses Gaia DR2 data to confirm in-situ star formation in the outskirts of the Large Magellanic Cloud, revealing recent star formation activity in regions previously thought to host only old stars.

Contribution

It provides the first direct kinematic evidence of recent star formation in the LMC's periphery, expanding understanding of its star formation history.

Findings

Four stars formed locally in the outskirts of the LMC.

Two stars likely expelled from inner regions.

Recent star formation occurs in low gas content areas.

Abstract

We explore the Gaia DR2 proper motions of six young, main-sequence stars, members of the Large Magellanic Cloud (LMC) reported by Moni Bidin et al. (2017). These stars are located in the outskirts of the disk, between 7 and 13 degrees from the LMC's center where there is very low H I content. Gaia DR2 proper motions confirm that four stars formed locally, in situ, while two are consistent with being expelled via dynamical interactions from inner, more gas-rich regions of the LMC. This finding establishes that recent star formation occurred in the periphery of the LMC, where thus far only old populations are known.