Attempting an accurate age estimate of the open cluster NGC 6633 using CoRoT and Gaia

Abstract

Asteroseismology of solar-like oscillations in giant stars allow the derivation of their masses and radii. For members of open clusters, this provides an age of the cluster that should be identical to the one derived from the colour-magnitude diagram, but independent of the uncertainties that are present for that type of analysis. We aim to identify and measure the properties of giant members of the open cluster NGC6633, and combine these with asteroseismic measurements to derive a precise and self-consistent cluster age. Importantly, we wish to constrain the effects of rotational mixing on stellar evolution, since assumptions about internal mixing can have a significant impact on stellar age estimates. We identify five giant members of NGC6633 using photometry and Gaia data, supplemented by spectroscopic literature measurements. These are combined with asteroseismic measurements from CoRoT data and compared to stellar-model isochrones. This constrains the interior mixing to a low level and enables the most precise, accurate and self-consistent age estimate so far for this cluster. Asteroseismology of the giants and the cluster colour-magnitude diagram provide self-consistent masses of the giant members and their radii constrain the stellar interior mixing to a low level. The [C/N] ratios and Li abundances also suggest that rotation has had very little influence on the evolution of the stars in NGC 6633. This results in an age estimate of 0.55+0.05-0.10 Gyr for NGC6633. Four giant members appear to be in the helium-core burning evolutionary phase as also expected from evolutionary timescales. For the largest giant, the evidence remains inconclusive. A comparison to other age and mass estimates for the same stars in the literature uncovers biases for automated age estimates of helium-core burning stars.

arXiv comment12 pages, 5 figures, accepted for publication in A&A, layout & affiliation corrections relative to v1

References in corpus (65)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• 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
• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• The K2 Mission: Characterization and Early results
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• The PLATO 2.0 Mission
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• Painting a portrait of the Galactic disc with its stellar clusters
• Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models
• Nominal values for selected solar and planetary quantities: IAU 2015 Resolution B3
• Asteroseismology of old open clusters with Kepler: direct estimate of the integrated RGB mass loss in NGC6791 and NGC6819
• Improving the open cluster census. II. An all-sky cluster catalogue with Gaia DR3
• Departures from LTE for neutral Li in late-type stars
• On the use of Gaia magnitudes and new tables of bolometric corrections
• Synthetic Stellar Photometry - I. General considerations and new transformations for broad-band systems
• Thermohaline instability and rotation-induced mixing. III - Grid of stellar models and asymptotic asteroseismic quantities from the pre-main sequence up to the AGB for low- and intermediate-mass stars at various metallicities
• Age determination for 269 $Gaia$ DR2 Open Clusters
• Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G=18.5
• StarHorse: A Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars
• Age dissection of the Milky Way discs: red giants in the Kepler field
• The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
• PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
• Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. II. age dependencies and new insights
• CNONa and 12C/13C in giants of 10 open clusters
• NGC 6819: testing the asteroseismic mass scale, mass loss, and evidence for products of non-standard evolution
• Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. I. Measurements, methods, and first results
• 3D NLTE spectral line formation of lithium in late-type stars
• The Gaia-ESO survey: the non-universality of the age-chemical-clocks-metallicity relations in the Galactic disc
• Metallicities for 13 nearby open clusters from high-resolution spectroscopy of dwarf and giant stars. Stellar metallicity, stellar mass, and giant planets
• Detection of solar-like oscillations in relics of the Milky Way: asteroseismology of K giants in M4 using data from the NASA K2 mission
• The Gaia-ESO survey: Calibrating a relationship between Age and the [C/N] abundance ratio with open clusters
• Abundance-age relations with red clump stars in open clusters
• The Gaia-ESO Survey: Evidence of atomic diffusion in M67?
• The Gaia-ESO survey: Mixing processes in low-mass stars traced by lithium abundance in cluster and field stars
• Membership, metallicity and lithium abundances for solar-type stars in NGC 6633
• Grids of stellar models with rotation VII: Models from 0.8 to 300 M${}_{\odot }$ at super-solar metallicity (Z = 0.020)
• The Gaia-ESO Survey: homogenisation of stellar parameters and elemental abundances
• Atmospheric parameters and chemical properties of red giants in the CoRoT asteroseismology fields
• Spectroscopic Study of the Open Cluster NGC 6811
• Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints
• The [Y/Mg] clock works for evolved solar metallicity stars
• Integrated Mass Loss of Evolved Stars in M4 using Asteroseismology
• The masses of retired A stars with asteroseismology: Kepler and K2 observations of exoplanet hosts
• Asteroseismology of the multiple stellar populations in the Globular Cluster M4
• Weighing in on the masses of retired A stars with asteroseismology: K2 observations of the exoplanet-host star HD 212771
• Asteroseismology of the young open cluster NGC 2516 I: Photometric and spectroscopic observations
• Asteroseismology of the Hyades red giant and planet host epsilon Tauri
• The Open Cluster Chemical Abundances and Mapping Survey: VII. APOGEE DR17 [C/N]-Age Calibration
• Convective-core overshoot and suppression of oscillations: Constraints from red giants in NGC6811
• Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. III. Constraints from a subgiant
• The blue straggler V106 in NGC6791: A prototype progenitor of old single giants masquerading as young
• Search for lithium-rich giants in 32 open clusters with high-resolution spectroscopy
• WIYN Open Cluster Study 89. M48 (NGC 2548) 2: Lithium Abundances in the 420 Myr Open Cluster M48 From Giants Through K Dwarfs
• Asteroseismology of overmassive, undermassive, and potential past members of the open cluster NGC6791
• Variability in the Massive Open Cluster NGC 1817 from K2: A Rich Population of Asteroseismic Red Clump, Eclipsing Binary, and Main Sequence Pulsating Stars
• An asteroseismic age estimate of the open cluster NGC 6866 using Kepler and Gaia
• Establishing the accuracy of asteroseismic mass and radius estimates of giant stars III. KIC4054905, an eclipsing binary with two 10 Gyr thick disk RGB stars
• The effect of the adiabatic assumption on asteroseismic scaling relations for luminous red giants
• Properties of the Hyades, the eclipsing binary HD27130, and the oscillating red giant $\epsilon$ Tau
• Investigating Gaia EDR3 parallax systematics using asteroseismology of Cool Giant Stars observed by Kepler, K2, and TESS I. Asteroseismic distances to 12,500 red-giant stars
• On the validity of the spectroscopic age indicators [Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] for giant stars
• The red giants in NGC 6633 as seen with CoRoT, HARPS and SOPHIE