Kavli Affiliate: Andrew Vanderburg
| First 5 Authors: Claudia Reyes, Dennis Stello, Marc Hon, Yaguang Li, Timothy R. Bedding
| Summary:
Sparked by the asteroseismic space revolution, ensemble studies have been
used to produce empirical relations linking observed seismic properties and
fundamental stellar properties. Cluster stars are particularly valuable because
they have the same metallicity, distance, and age, thus reducing scatter to
reveal smoother relations. We present the first study of a cluster that spans
the full evolutionary sequence from subgiants to core helium-burning red giants
using asteroseismology to characterise the stars in M67, including a yellow
straggler. We use Kepler/K2 data to measure seismic surface gravity, examine
the potential influence of core magnetic fields, derive an empirical expression
for the seismic surface term, and determine the phase term $epsilon$ of the
asymptotic relation for acoustic modes, extending its analysis to evolutionary
states previously unexplored in detail. Additionally, we calibrate seismic
scaling relations for stellar mass and radius, and quantify their systematic
errors if surface term corrections are not applied to state-of-the-art stellar
models. Our masses show that the Reimers mass loss parameter can not be larger
than $eta$ $sim$ 0.23 at the 2-$sigma$ level. We use isochrone models
designed for M67 and compare their predictions with individual mode
frequencies. We find that the seismic masses for subgiants and red giant branch
stars align with the isochrone-predicted masses as per their luminosity and
colour. However, our results are inconsistent with the mass of one of the
stellar components of an eclipsing binary system near the TAMS. We use
traditional seismic $chi^2$ fits to estimate a seismic cluster age of 3.95
$pm$ 0.35 Gyrs.
| Search Query: ArXiv Query: search_query=au:”Andrew Vanderburg”&id_list=&start=0&max_results=3