The Distances to Open Clusters from Main-Sequence Fitting. I. New Models and a Comparison to the Properties of the Hyades Eclipsing Binary vB 22

Abstract

In the first of a new series of papers on open cluster distances, we use updated stellar evolution models to construct an isochrone appropriate for the Hyades, and compare it with the Hyades eclipsing binary system vB 22. We find that the absolute and relative luminosities of the two stars are in good agreement with the model, but the radii do not match the values inferred from eclipse data. We present evidence that there is a consistency problem with the flux ratios and the inferred radii, and discuss possible theoretical effects that could be responsible for the mismatch in the radii. We derive a helium abundance for the Hyades of Y = 0.271 \pm 0.006, which is equal within the errors to the Sun's initial helium abundance even though the Hyades is considerably more metal-rich.

arXiv commentAccepted for publication in Astrophysical Journal

References in corpus (20)

• Color Transformations for the 2MASS Second Incremental Data Release
• Solar Models: current epoch and time dependences, neutrinos, and helioseismological properties
• A standard stellar library for evolutionary synthesis: II. The M dwarf extension
• Database of Geneva stellar evolution tracks and isochrones for UBVRIJHKLL'M, HST-WFPC2, Geneva and Washington photometric systems
• Model Atmospheres for M (Sub)Dwarfs: I. The base model grid
• The Y^2 Stellar Evolutionary Tracks
• The Problem of Hipparcos Distances to Open Clusters: I. Constraints from Multicolor Main Sequence Fitting
• A Hipparcos study of the Hyades open cluster: Improved colour-absolute magnitude and Hertzsprung-Russell diagrams
• How much do helioseismological inferences depend upon the assumed reference model?
• Why are the K dwarfs in the Pleiades so Blue?
• Rotational velocities of low-mass stars in the Pleiades and Hyades
• Correlated errors in Hipparcos parallaxes towards the Pleiades and the Hyades
• Rotation and activity in the solar-metallicity open cluster NGC2516
• The problem of the Pleiades distance. Constraints from Stromgren photometry of nearby field stars
• The Problem of Hipparcos Distances to Open Clusters. II. Constraints from Nearby Field Stars
• WIYN Open Cluster Study XVI: Optical/Infrared Photometry and Comparisons With Theoretical Isochrones
• The Open Cluster Distance Scale: A New Empirical Approach
• The Distances to Open Clusters as Derived from Main-sequence Fitting. II. Construction of Empirically Calibrated Isochrones
• Stellar models and Hyades: the Hipparcos test
• A Precision test of Hipparcos systematics towards the Hyades

Cited by in corpus (54)

• The Dartmouth Stellar Evolution Database
• The Ages of Stars
• Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue
• A Revised Effective Temperature Scale for the Kepler Input Catalog
• Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale
• The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones
• On the Formation of Multiple Stellar Populations in Globular Clusters
• The Age of AB Dor
• Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. I. Crowded Field Photometry and Cluster Fiducial Sequences in ugriz
• The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
• A deep all-sky census of the Hyades
• The Revolution Revolution: magnetic morphology driven spin-down
• Fitting the young main-sequence; distances, ages and age spreads
• The Stellar Metallicity Distribution Function of the Galactic Halo from SDSS Photometry
• The Helium abundance and Delta Y / Delta Z in Lower Main Sequence stars
• Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. II. Test of Theoretical Stellar Isochrones
• Brown dwarfs and very low mass stars in the Hyades cluster : a dynamically evolved mass function
• On the current status of open-cluster parameters
• Red Giant Branch Bump Brightness and Number Counts in 72 Galactic Globular Clusters Observed with the Hubble Space Telescope
• Empirical isochrones and relative ages for young stars, and the radiative-convective gap
• Age Determination for 346 Nearby Stars in the Herschel DEBRIS Survey
• The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
• Main-Seqence Fitting Distance to the sigma Ori Cluster
• The exoplanet-host star iota Horologii: an evaporated member of the primordial Hyades cluster
• Deep MMT Transit Survey of the Open Cluster M37 I: Observations and Cluster Parameters
• Oxygen from the Lambda 7774 High-Excitation Triplet in Open Cluster Dwarfs: Hyades
• Why are rapidly rotating M dwarfs in the Pleiades so (infra)red? New period measurements confirm rotation-dependent color offsets from the cluster sequence
• The Detection of Low Mass Companions in Hyades Cluster Spectroscopic Binary Stars
• Pre-main-sequence isochrones -- III. The Cluster Collaboration isochrone server
• WIYN Open Cluster Study. XXVI. Improved kinematic membership and spectroscopy of IC 2391
• Boron Abundances Across the "Li-Be Dip" in the Hyades
• Simulations of the Hyades
• Modelling the components of binaries in Hyades: The dependence of the mixing-length parameter on stellar mass
• A Photometric Metallicity Estimate of the Virgo Stellar Overdensity
• Deep, Wide-field CCD Photometry for the Open Cluster NGC3532
• Fe I and Fe II Abundances of Solar-Type Dwarfs in the Pleiades Open Cluster
• Spectroscopic metallicity determinations for W~UMa-type binary stars
• Fiducial Stellar Population Sequences for the VJKs Photometric System
• A Pre-Gaia Census of Nearby Stellar Groups
• The GALAH survey: Chemical homogeneity of the Orion complex
• Asteroseismology of the Hyades with K2: first detection of main-sequence solar-like oscillations in an open cluster
• Isochrone fitting to the open cluster M67 in the era of Gaia and improved model physics
• The Distances to Open Clusters from Main-Sequence Fitting. V. Extension of Color Calibration and Test using Cool and Metal-Rich Stars in NGC 6791
• Spectroscopic Survey of G and K Dwarfs in the Hipparcos Catalog. I. Comparison between the Hipparcos and Photometric Parallaxes
• Comparison of the Asteroseismic Mass Scale of Red Clump Giants with Photometric Mass Estimates
• A Blueprint for the Milky Way's Stellar Populations. II. Improved Isochrone Calibration in the SDSS and Pan-STARRS Photometric Systems
• F Turnoff Distribution in the Galactic Halo Using Globular Clusters as Proxies
• Spectroscopic Determination of Stellar Parameters and Oxygen Abundances for Hyades/Field G-K Dwarfs
• A Blueprint for the Milky Way's Stellar Populations. IV. A String of Pearls $-$ the Galactic Starburst Sequence
• UBVI CCD Photometry of the Old Open Cluster NGC 1193
• A Bound on the Light Emitted During the TP-AGB Phase
• Photometric survey of marginally investigated open clusters: I. Basel 11b, King 14, Czernik 43
• A uvbyCaHbeta CCD Analysis of the Open Cluster Standard, M67,and its Relation to NGC 752
• New Methods for Determining the Ages of PMS Stars