Asteroseismic Study of Subgiants and Giants of the Open Cluster M67 using Kepler/K2: Expanded Sample and Precise Masses

Abstract

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.

arXiv commentAccepted for publication in the Monthly Notices of the Royal Astronomical Society (MNRAS)

References in corpus (82)

• Planck 2015 results. XIII. Cosmological parameters
• Gaia Data Release 2. Summary of the contents and survey properties
• Modules for Experiments in Stellar Astrophysics (MESA)
• Gaia Data Release 3: Summary of the content and survey properties
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• The K2 Mission: Characterization and Early results
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• Gaia Data Release 2: Photometric content and validation
• The GALAH+ Survey: Third Data Release
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• Asteroseismology of Solar-Type and Red-Giant Stars
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• Testing Scaling Relations for Solar-Like Oscillations from the Main Sequence to Red Giants using Kepler Data
• Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
• Correcting stellar oscillation frequencies for near-surface effects
• Probing the interior physics of stars through asteroseismology
• The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8
• The Second APOKASC Catalog: The Empirical Approach
• On the use of Gaia magnitudes and new tables of bolometric corrections
• Calculating asteroseismic diagrams for solar-like oscillations
• On the triple origin of blue stragglers
• Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure
• Standing on the shoulders of Dwarfs: the $Kepler$ asteroseismic LEGACY sample I - oscillation mode parameters
• The relation between $\Delta \nu$ and ${\nu }_{max}$ for solar-like oscillations
• A new correction of stellar oscillation frequencies for near-surface effects
• Planetary Candidates from the First Year of the K2 Mission
• Stellar population synthesis based modelling of the Milky Way using asteroseismology of 13000 Kepler red giants
• Age dissection of the Milky Way discs: red giants in the Kepler field
• PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
• Asteroseismology Can Reveal Strong Internal Magnetic Fields in Red Giant Stars
• Asteroseismology of the open clusters NGC 6791, NGC 6811, and NGC 6819 from nineteen months of Kepler photometry
• A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars
• Asymptotic and measured large frequency separations
• Measuring the vertical age structure of the Galactic disc using asteroseismology and SAGA
• The First APOKASC Catalog of Kepler Dwarf and Subgiant Stars
• DIAMONDS: a new Bayesian Nested Sampling tool. Application to Peak Bagging of solar-like oscillations
• Rotation periods for cool stars in the 4 Gyr-old open cluster M67, the solar-stellar connection, and the applicability of gyrochronology to at least solar age
• Chronologically dating the early assembly of the Milky Way
• Stellar Radial Velocities in the Old Open Cluster M67 (NGC 2682) I. Memberships, Binaries, and Kinematics
• Determining stellar parameters of asteroseismic targets: going beyond the use of scaling relations
• Amplitudes of Stellar Oscillations: The Implications for Asteroseismology
• Oscillating K giants with the WIRE satellite: determination of their asteroseismic masses
• NGC 6819: testing the asteroseismic mass scale, mass loss, and evidence for products of non-standard evolution
• Establishing the accuracy of asteroseismic mass and radius estimates of giant stars. I. Three eclipsing systems at [Fe/H]~ -0.3 and the need for a large high-precision sample
• The GALAH survey: effective temperature calibration from the InfraRed Flux Method in the Gaia system
• Deep 2MASS Photometry of M67 and Calibration of the Main Sequence J-Ks Color Difference as an Age Indicator
• Asteroseismic signatures of evolving internal stellar magnetic fields
• Detection of solar-like oscillations in relics of the Milky Way: asteroseismology of K giants in M4 using data from the NASA K2 mission
• Changing the ${\nu }_{\max }$ Scaling Relation: The Need For a Mean Molecular Weight Term
• The K2 M67 Study: Revisiting old friends with K2 reveals oscillating red giants in the open cluster M67
• Interaction Between Convection and Pulsation
• Improvements to Stellar Structure Models, Based on a Grid of 3D Convection Simulations. I. $T(\tau )$-Relations
• Classically and Asteroseismically constrained 1D Stellar Evolution Models of $\alpha$ Centauri A and B using Empirical Mixing Length Calibrations
• The BAyesian STellar Algorithm (BASTA): a fitting tool for stellar studies, asteroseismology, exoplanets, and Galactic archaeology
• New light on the Gaia DR2 parallax zero-point: influence of the asteroseismic approach, in and beyond the Kepler field
• Suppression of quadrupole and octupole modes in red giants observed by Kepler
• The end of the white dwarf cooling sequence in M 67
• How accurate are stellar ages based on stellar models ? I. The impact of stellar models uncertainties
• Asteroseismology of 36 Kepler subgiants -- II: Determining ages from detailed modelling
• Asteroseismology of 3,642 Kepler Red Giants: Correcting the Scaling Relations based on Detailed Modeling
• Differential population studies using asteroseismology: solar-like oscillating giants in CoRoT fields LRc01 and LRa01
• Nonlinear seismic scaling relations
• A prescription for the asteroseismic surface correction
• Integrated Mass Loss of Evolved Stars in M4 using Asteroseismology
• IAU 2015 Resolution B2 on Recommended Zero Points for the Absolute and Apparent Bolometric Magnitude Scales
• Automated extraction of oscillation parameters for Kepler observations of solar-type stars
• Fast and Automated Peak Bagging with DIAMONDS (FAMED)
• Isochrone fitting to the open cluster M67 in the era of Gaia and improved model physics
• A chemical study of M67 candidate blue stragglers and evolved blue stragglers observed with APOGEE DR14
• Multi-site campaign on the open cluster M67. I. Observations and photometric reductions
• Comparison of the Asteroseismic Mass Scale of Red Clump Giants with Photometric Mass Estimates
• The K2 M67 Study: Precise Mass for a Turnoff Star in the Old Open Cluster M67
• A Unified Exploration of the Chronology of the Galaxy
• A novel analytic atmospheric $T(\tau )$ relation for stellar models
• A spectroscopic study of the blue stragglers in M67
• On the seismic scaling relations $\Delta \nu -\bar{\rho }$ and ${\nu }_{\max }-{\nu }_{\mathrm{c}}$
• Testing the Breakdown of the Asteroseismic Scaling Relations in Luminous Red Giants

Cited by in corpus (7)

• Evidence that Mass Loss on the Red Giant Branch Decreases with Metallicity
• Asteroseismology of the young open cluster NGC 2516 II. Constraining cluster age using gravity-mode pulsators
• Asteroseismology of the G8 subgiant beta Aquilae with SONG-Tenerife, SONG-Australia and TESS
• Matching seismic masses for RR Lyrae-type and oscillating red horizontal-branch stars in M4
• Stellar age determination using deep neural networks: Isochrone ages for 1.3 million stars, based on BaSTI, MIST, PARSEC, Dartmouth and SYCLIST evolutionary grids
• Asteroseismology of red giants in the globular cluster 47 Tuc using the HST
• Asteroseismic mass and radius of the naked-eye red giant HD145250