Veyette, Mark J.Muirhead, Philip S.2018-12-122018-12-122018-08-20Mark J Veyette, Philip S Muirhead. 2018. "Chemo-kinematic Ages of Eccentric-planet-hosting M Dwarf Stars." Astrophysical Journal, Volume 863, Issue 2. https://doi.org/10.3847/1538-4357/aad40e0004-637X1538-4357https://hdl.handle.net/2144/32923The M dwarf stars are exciting targets for exoplanet investigations; however, their fundamental stellar properties are difficult to measure. Perhaps the most challenging property is stellar age. Once on the main sequence, M dwarfs change imperceptibly in their temperature and luminosity, necessitating novel statistical techniques for estimating their ages. In this paper, we infer ages for known eccentric-planet-hosting M dwarfs using a combination of kinematics and α-element enrichment, both shown to correlate with age for Sun-like FGK stars. We calibrate our method on FGK stars in a Bayesian context. To measure α-enrichment, we use publicly available spectra from the CARMENES exoplanet survey and a recently developed [Ti/Fe] calibration utilizing individual Ti i and Fe i absorption lines in the Y band. Tidal effects are expected to circularize the orbits of short-period planets on short timescales; however, we find a number of mildly eccentric, close-in planets orbiting old (~8 Gyr) stars. For these systems, we use our ages to constrain the tidal dissipation parameter of the planets, Q p. For two mini-Neptune planets, GJ 176 b and GJ 536 b, we find that they have Q p values more similar to the ice giants than to the terrestrial planets in our solar system. For GJ 436 b, we estimate an age of ${8.9}_{-2.1}^{+2.3}\,\mathrm{Gyr}$ and constrain the Q p to be >105, in good agreement with constraints from its inferred tidal heating. We find that GJ 876 d has likely undergone significant orbital evolution over its ${8.4}_{-2.0}^{+2.2}\,\mathrm{Gyr}$ lifetime, potentially influenced by its three outer companions that orbit in a Laplace resonance.© 2018. The American Astronomical Society. All rights reserved.Science & technologyPhysical sciencesAstronomy & astrophysicsPlanets and satellitesGaseous planetsStars: abundancesStars: fundamental parametersStars: late-typeStars: low-massHR 1614Astronomical and space sciencesOrganic chemistryPhysical chemistry (incl. structural)Astronomy and astrophysicsArticle10.3847/1538-4357/aad40e0000-0002-0638-8822 (Muirhead, Philip S)