TESS Asteroseismology of α Mensae: Benchmark Ages for a G7 Dwarf and Its M Dwarf Companion

Chontos, Ashley; Huber, Daniel; Berger, Travis A.; Kjeldsen, Hans; Serenelli, Aldo M.; Silva Aguirre, Victor; Ball, Warrick H.; Basu, Sarbani; Bedding, Timothy R.; Chaplin, William J.; Claytor, Zachary R.; Corsaro, Enrico; Garcia, Rafael A.; Howell, Steve B.; Lundkvist, Mia S.; Mathur, Savita; Metcalfe, Travis S.; Nielsen, Martin B.; Mian Joel Ong, Jia; Çelik Orhan, Zeynep; Örtel, Sibel; Salama, Maissa; Stassun, Keivan G.; Townsend, R. H. D.; van Saders, Jennifer L.; Winther, Mark; Yildiz, Mutlu; Butler, R. Paul; Tinney, C. G.; Wittenmyer, Robert A.
Bibliographical reference

The Astrophysical Journal

Advertised on:
12
2021
Number of authors
30
IAC number of authors
1
Citations
22
Refereed citations
15
Description
Asteroseismology of bright stars has become increasingly important as a method to determine the fundamental properties (in particular ages) of stars. The Kepler Space Telescope initiated a revolution by detecting oscillations in more than 500 main-sequence and subgiant stars. However, most Kepler stars are faint and therefore have limited constraints from independent methods such as long-baseline interferometry. Here we present the discovery of solar-like oscillations in α Men A, a naked-eye (V = 5.1) G7 dwarf in TESS's southern continuous viewing zone. Using a combination of astrometry, spectroscopy, and asteroseismology, we precisely characterize the solar analog α Men A (T eff = 5569 ± 62 K, R ⋆ = 0.960 ± 0.016 R ⊙, M ⋆ = 0.964 ± 0.045 M ⊙). To characterize the fully convective M dwarf companion, we derive empirical relations to estimate mass, radius, and temperature given the absolute Gaia magnitude and metallicity, yielding M ⋆ = 0.169 ± 0.006 M ⊙, R ⋆ = 0.19 ± 0.01 R ⊙, and T eff = 3054 ± 44 K. Our asteroseismic age of 6.2 ± 1.4 (stat) ± 0.6 (sys) Gyr for the primary places α Men B within a small population of M dwarfs with precisely measured ages. We combined multiple ground-based spectroscopy surveys to reveal an activity cycle of P = 13.1 ± 1.1 yr for α Men A, a period similar to that observed in the Sun. We used different gyrochronology models with the asteroseismic age to estimate a rotation period of ~30 days for the primary. Alpha Men A is now the closest (d = 10 pc) solar analog with a precise asteroseismic age from space-based photometry, making it a prime target for next-generation direct-imaging missions searching for true Earth analogs.
Related projects
Helio and Asteroseismology
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur