Distance and Tangential Velocity of the Main Ionizing Star in the North America/Pelican Nebulae with Gaia EDR3

TL;DR

This study uses Gaia EDR3 data to analyze the distance and tangential velocity of the Bajamar Star in the North America/Pelican Nebulae, suggesting it may have escaped from a stellar subgroup.

Contribution

It provides updated Gaia EDR3 measurements showing the star's velocity discrepancy persists, indicating a possible ejection from a stellar subgroup.

Findings

Parallax discrepancy resolved with Gaia EDR3

Velocity difference remains (~6 km/s)

Star likely escaped from a stellar subgroup

Abstract

The Bajamar Star is an early O star that ionizes the North America/Pelican Nebulae. In projection, it is near the geometric center of the H II region, but appears to lie outside any of the main stellar subgroups. Furthermore, in Gaia DR2, there were slight discrepancies between this star and the rest of the system in parallax (2$\sigma$ larger) and relative tangential velocity (~6 km/s). Using Gaia EDR3, we find that the parallax discrepancy has disappeared, but the velocity difference remains. These results are consistent with the star having escaped from a subgroup.