Beyond Gaia: Asteroseismic Distances of M Giants Using Ground-based Transient Surveys
2020
ASTRONOMICAL JOURNAL
DOI
10.3847/1538-3881/ab91bf
Evolved stars near the tip of the red giant branch show solar-like oscillations with periods spanning hours to months and amplitudes ranging from similar to 1 mmag to similar to 100 mmag. The systematic detection of the resulting photometric variations with ground-based telescopes would enable the application of asteroseismology to a much larger and more distant sample of stars than is currently accessible with space-based telescopes such as Kepler or the ongoing Transiting Exoplanet Survey Satellite mission. We present an asteroseismic analysis of 493 M giants using data from two ground-based surveys: the Asteroid Terrestrial-impact Last Alert System (ATLAS) and the All-Sky Automated Survey for Supernovae (ASAS-SN). By comparing the extracted frequencies with constraints from Kepler, the Sloan Digital Sky Survey Apache Point Observatory Galaxy Evolution Experiment, and Gaia we demonstrate that ground-based transient surveys allow accurate distance measurements to oscillating M giants with a precision of similar to 15%. Using stellar population synthesis models we predict that ATLAS and ASAS-SN can provide asteroseismic distances to similar to 2 x 10(6)galactic M giants out to typical distances of 20-50 kpc, vastly improving the reach of Gaia and providing critical constraints for Galactic archeology and galactic dynamics.