On using the CMD morphology of M67 to test solar abundances

Abstract

The open cluster M67 has solar metallicity and an age of about 4Gyr. The turn-off mass is close to the minimum mass for which solar metallicity stars develop a convective core during main sequence evolution as a result of the development of hydrogen burning through the CNO-cycle. The morphology of the color-magnitude-diagram (CMD) of M67 around the turn-off shows a clear hook-like feature, direct sign that stars close to the turn-off have convective cores. VandenBerg et al. investigated the possibility of using the morphology of the M67 turn-off to put constraints on the solar metallicity, particularly CNO elements, for which solar abundances have been revised downwards by more than 30% over the last few years. Here, we extend their work filling in the gaps in their analysis. To this aim, we compute isochrones appropriate for M67 using new (low metallicity) and old (high metallicity) solar abundances and study whether the characteristic turn-off in the CMD of M67 can be reproduced or not. We also study the importance of other constitutive physics on determining the presence of such a hook, particularly element diffusion, overshooting and nuclear reaction rates. We find that using the new solar abundance determinations, with low CNO abundances, makes it more difficult to reproduce the characteristic CMD of M67. This result is in agreement with results by VandenBerg et al. However, changes in the constitutive physics of the models, particularly overshooting, can influence and alter this result to the extent that isochrones constructed with models using low CNO solar abundances can also reproduce the turn-off morphology in M67. We conclude that only if all factors affecting the turn-off morphology are completely under control (and this is not the case), M67 could be used to put constraints on solar abundances.

11 pages including 9 figures and 1 table. Submitted to ApJ

References in corpus (36)

• The chemical composition of the Sun
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Dartmouth Stellar Evolution Database
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Low Temperature Opacities
• Solar Models with Helium and Heavy Element Diffusion
• New solar opacities, abundances, helioseismology, and neutrino fluxes
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• The Victoria-Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting
• Helioseismological Implications of Recent Solar Abundance Determinations
• Constraining solar abundances using helioseismology
• The photospheric solar oxygen project: I. Abundance analysis of atomic lines and influence of atmospheric models
• Element abundances of unevolved stars in the open cluster M 67
• What Is The Neon Abundance Of The Sun?
• The bottleneck of the CNO burning and the age of the Globular Clusters
• On the opacity change required to compensate for the revised solar composition
• Color transformations and bolometric corrections for Galactic halo stars: alpha-enhanced vs scaled-solar results
• New evolutionary models for massive ZZ Ceti stars: I. First results for their pulsational properties
• Models for Solar Abundance Stars with Gravitational Settling and Radiative Accelerations: Application to M67 and NGC188
• Heavy Element Diffusion in Metal Poor Stars
• A High Relative-Precision Color-Magnitude Diagram of M67
• Precision study of ground state capture in the 14N(p,gamma)15O reaction
• Determining solar abundances using helioseismology
• The Ne/O abundance ratio in the quiet Sun
• Solar heavy element abundance: constraints from frequency separation ratios of low-degree p modes
• On the Use of Blanketed Atmospheres as Boundary Conditions for Stellar Evolutionary Models
• Theoretical Uncertainties in Red Giant Branch Evolution: The Red Giant Branch Bump
• A Constraint on Z_\odot from Fits of Isochrones to the Color-Magnitude Diagram of M67
• A new approach to the solar oxygen abundance problem
• Influence of two updated nuclear reaction rates on the evolution of low and intermediate mass stars
• The Open Cluster Distance Scale: A New Empirical Approach
• Evolution of a 3 \msun star from the main sequence to the ZZ Ceti stage: the role played by element diffusion
• The Unevolved Main Sequence of Nearby Field Stars and the Open Cluster Distance Scale
• Impact of the new solar abundances on the calibration of the PMS binary system RS Cha
• Diffusive convective overshoot in core He-burning intermediate mass stars. I: the LMC metallicity
• The Solar Photospheric Nitrogen Abundance: Determination with 3D and 1D Model Atmospheres

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