zoomies: A tool to infer stellar age from vertical action in Gaia data

TL;DR

This paper introduces 'zoomies', an open-source tool that infers stellar ages from Gaia data using vertical action, enabling large-scale demographic studies despite inherent uncertainties.

Contribution

The study develops a new framework to predict stellar ages from dynamical properties, calibrated with asteroseismic and isochrone ages, and provides an open-source tool for the community.

Findings

Dynamical age estimates are generally mass independent.

'Zoomies' can infer ages for stars using Gaia's vertical action data.

The method shows reasonable agreement with cluster and asteroseismic ages.

Abstract

Stellar age measurements are fundamental to understanding a wide range of astronomical processes, including Galactic dynamics, stellar evolution, and planetary system formation. However, extracting age information from main-sequence stars is complicated, with techniques often relying on age proxies in the absence of direct measurements. The Gaia data releases have enabled detailed studies of the dynamical properties of stars within the Milky Way, offering new opportunities to understand the relationship between stellar age and dynamics. In this study, we leverage high-precision astrometric data from Gaia DR3 to construct a stellar age prediction model based only on stellar dynamical properties, namely the vertical action. We calibrate two distinct, hierarchical stellar age--vertical action relations, first employing asteroseismic ages for red-giant-branch stars, then isochrone ages for main-sequence turn-off stars. We describe a framework called "zoomies" based on this calibration, by which we can infer ages for any star given its vertical action. This tool is open-source and intended for community use. We compare dynamical age estimates from "zoomies" with age measurements from open clusters and asteroseismology. We use "zoomies" to generate and compare dynamical age estimates for stars from the Kepler, K2, and TESS exoplanet transit surveys. While dynamical age relations are associated with large uncertainty, they are generally mass independent and depend on homogeneously measured astrometric data. These age predictions are uniquely useful for large-scale demographic investigations, especially in disentangling the relationship between planet occurrence, metallicity, and age for low-mass stars.