The variability and radial velocity of planetary nebulae central stars

TL;DR

This study leverages Gaia DR3 data to identify new close binary central stars of planetary nebulae and expand the understanding of their radial velocities, contributing significantly to the knowledge of PNe evolution and galactic dynamics.

Contribution

It provides the first large collection of trustworthy variability data for CSs and identifies 58 new close binary candidates, doubling the known sample size.

Findings

Discovered 58 new close binary CS candidates.

Measured radial velocities for 51 PNe, 24 for the first time.

Gaia RV measurements generally agree with nebular emission line data.

Abstract

The extremely accurate estimates of stellar variability and radial velocity in the Gaia Data Release 3 (Gaia DR3) have enabled us to examine the close binarity and radial velocity (RV) of central stars (CSs) of planetary nebulae (PNe). This study is twofold: (1) searching for new close binary CSs candidates to better understand how binarity affects the formation and evolution of PNe; and (2) extending the sample size of known RV of PNe in order to understand their kinematics and the dynamics of the Milky Way. As a target sample, we used all true, possible, and likely PNe available in the literature. Then, we looked for their matched Gaia DR3 sources that provide measurements of variability and RV. As a result, we detected the first large collection of trustworthy photometric variability of 26 symbiotic stars (SySts) and 82 CSs. In this CS group, there are 24 sources already classified as true close binary CSs in the literature. Hence, we discovered 58 new close binary CS candidates. This close binary (CB) sample represents more than half of what is currently available in the literature. In addition, we identified the radial velocities for 51 PNe. To our knowledge, 24 of these were measured for the first time. The RV measurements predicted by Gaia, based on the Doppler shift of the CS absorption lines, and those derived from nebular emission lines, show satisfactory agreement except for a few extremely high-velocity PNe.