Untangling the Galaxy. IV. Empirical Constraints on Angular Momentum Evolution and Gyrochronology for Young Stars in the Field

Abstract

We present a catalog of ~100,000 periodic variable stars in TESS FFI data among members of widely distributed moving groups identified with Gaia in the previous papers in the series. By combining the periods from our catalog attributable to rotation with previously derived rotation periods for benchmark open clusters, we develop an empirical gyrochronology relation of angular momentum evolution that is valid for stars with ages 10-1000 Myr. Excluding stars rotating faster than 2 days, which we find are predominantly binaries, we achieve a typical age precision of ~0.2-0.3 dex and improving at older ages. Importantly, these empirical relations apply to not only FGK-type stars but also M-type stars, due to the angular momentum distribution being much smoother, simpler, continuous and monotonic as compared to the rotation period distribution. As a result, we are also able to begin tracing in fine detail the nature of angular momentum loss in low-mass stars as functions of mass and age. We characterize the stellar variability amplitudes of the cool stars as functions of mass and age, which may correlate with the starspot covering fractions. We also identify pulsating variables among the hotter stars in the catalog, including $\delta$ Scuti, $\gamma$ Dor and SPB-type variables. These data represent an important step forward in being able to estimate precise ages of FGK- and M-type stars in the field, starting as early as the pre-main-sequence phase of evolution.

24 pages, 14 figures, accepted to AJ

References in corpus (26)

• The Transiting Exoplanet Survey Satellite
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Painting a portrait of the Galactic disc with its stellar clusters
• The Mass-Dependence of Angular Momentum Evolution in Sun-Like Stars
• K2 rotation periods for low-mass Hyads and a quantitative comparison of the distribution of slow rotators in the Hyades and Praesepe
• Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars
• A Temporary Epoch of Stalled Spin-Down for Low-Mass Stars: Insights from NGC 6811 with Gaia and Kepler
• Placing the spotted T Tauri star LkCa 4 on an HR diagram
• Close companions around young stars
• Very regular high-frequency pulsation modes in young intermediate-mass stars
• The temporal evolution of neutron-capture elements in the Galactic discs
• Stellar rotation periods from K2 Campaigns 0-18 -- Evidence for rotation period bimodality and simultaneous variability decrease
• Weakened magnetic braking supported by asteroseismic rotation rates of Kepler dwarfs
• Autonomous Gaussian Decomposition
• The period-luminosity relation for delta Scuti stars using Gaia DR2 parallaxes
• Stellar activity with LAMOST. I. Spot configuration in Pleiades
• From Starspots to Stellar Coronal Mass Ejections -- Revisiting Empirical Stellar Relations
• Exploring the evolution of stellar rotation using Galactic kinematics
• Rotation and Lithium Confirmation of a 500 Parsec Halo for the Open Cluster NGC 2516
• Rotation periods for cool stars in the open cluster NGC 3532. The transition from fast to slow rotation
• The rotation period distribution of the rich Pleiades-age Southern open cluster NGC 2516. Existence of a representative zero-age main sequence distribution
• Systematics-insensitive Periodogram for finding periods in TESS observations of long-period rotators
• Rotation Distributions around the Kraft Break with TESS and Kepler: The Influences of Age, Metallicity, and Binarity
• Determining the seismic age of the young open cluster $\alpha$ Per using $\delta$ Scuti stars
• Stellar dating using chemical clocks and Bayesian inference