The Ages of Early-Type Stars: Str\"omgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets

TL;DR

This paper develops and validates a photometric method to accurately determine the ages of early-type stars, aiding the identification of promising targets for exoplanet imaging surveys.

Contribution

It introduces a calibrated, validated approach using Strömgren photometry and stellar models to estimate ages of early-type stars, including field stars and exoplanet hosts.

Findings

Validated method against benchmark clusters.

Achieved accurate age estimates for 3493 field stars.

Demonstrated applicability to exoplanet host stars.

Abstract

Age determination is undertaken for nearby early-type (BAF) stars, which constitute attractive targets for high-contrast debris disk and planet imaging surveys. Our analysis sequence consists of: acquisition of uvby{\beta} photometry from catalogs, correction for the effects of extinction, interpolation of the photometry onto model atmosphere grids from which atmospheric parameters are determined, and finally, comparison to the theoretical isochrones from pre-main sequence through post-main sequence stellar evolution models, accounting for the effects of stellar rotation. We calibrate and validate our methods at the atmospheric parameter stage by comparing our results to fundamentally determined Teff and log g values. We validate and test our methods at the evolutionary model stage by comparing our results on ages to the accepted ages of several benchmark open clusters (IC 2602, {\alpha} Persei, Pleiades, Hyades). Finally, we apply our methods to estimate stellar ages for 3493 field stars, including several with directly imaged exoplanet candidates.