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Related papers: The YY Isochrones for alpha-element Enhanced Mixtu…

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We create isochrones of M67 using the Yale Rotating Stellar Evolution Code. In addition to metallicity, parameters that are traditionally held fixed, such as the mixing length parameter and initial helium abundance, also vary. The amount of…

Solar and Stellar Astrophysics · Physics 2017-11-08 Lucas S. Viani , Sarbani Basu

We have performed the first extensive analysis of the impact of an [alpha/Fe]>0 metal distribution on broadband colors in the parameter space (surface gravity, effective temperature, metal content) covered by Galactic globular cluster…

Astrophysics · Physics 2009-11-10 Santi Cassisi , Maurizio Salaris , Fiorella Castelli , Adriano Pietrinferni

As part of an ongoing program to measure detailed chemical abundances in nearby galaxies, we use a sample of young to intermediate age clusters in the Large Magellanic Cloud with ages of 10 Myr to 2 Gyr to evaluate the effect of isochrone…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. E. Colucci , R. A. Bernstein

We fit the upper main sequence of the Praesepe and Hyades open clusters using stellar models with and without rotation. When neglecting rotation, we find that no single isochrone can fit the entire upper main sequence at the clusters'…

Solar and Stellar Astrophysics · Physics 2015-07-02 Timothy D. Brandt , Chelsea X. Huang

We present ages, [Fe/H] and abundances of the alpha elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters in M31, which were obtained from high resolution, high signal-to-noise ratio (SNR$>60$)…

Astrophysics of Galaxies · Physics 2015-06-23 J. E. Colucci , R. A. Bernstein , J. Cohen

The last decade showed an impressive observational effort from the photometric and spectroscopic point of view for ancient stellar clusters in our Galaxy and beyond. The theoretical interpretation of these new observational results requires…

Solar and Stellar Astrophysics · Physics 2013-06-06 M. Dell'Omodarme , G. Valle , S. Degl'Innocenti , P. G. Prada Moroni

The effect of atomic diffusion on the Main Sequence (MS) of metal-poor low mass stars is investigated. Since diffusion alters the stellar surface chemical abundances with respect to their initial values, one must ensure - by calibrating the…

Astrophysics · Physics 2007-05-23 M. Salaris , M. A. T. Groenewegen , A. Weiss

We present a new version of the compiled catalogue of nearby stars for which was published the spectoscopically determined effective temperatures, surface gravities, and abundances of iron, magnesium, calcium, silicon, and titanium.…

Astrophysics · Physics 2007-10-25 T. V. Borkova , M. S. Katchieva , B. A. Marsakov , D. M. Pitkina

Stellar evolutionary tracks for $0.12 \le M/M_\odot \le 1.0$ have been computed for each of several variations in the abundances of C, N, and O, assuming mass-fraction helium abundances $Y = 0.25$ and $0.29$, and 11 metallicities in the…

Solar and Stellar Astrophysics · Physics 2022-11-30 Don A. VandenBerg

We present the results of determination of the age, helium mass fraction (Y) in terms of the used stellar evolutionary models, metallicity ([Fe/H]), and abundances of the elements C, O, Na, Mg, Ca, Ti, Cr and Mn for 26 globular clusters of…

Astrophysics of Galaxies · Physics 2020-09-07 M. E. Sharina , V. V. Shimansky , N. N. Shimanskaya

The Gaia mission has provided highly accurate observations that have significantly reduced the scatter in the colour-magnitude diagrams of open clusters. As a result of the improved isochrone sequence of the open cluster M67, we have…

Solar and Stellar Astrophysics · Physics 2024-07-09 Claudia Reyes , Dennis Stello , Marc Hon , Regner Trampedach , Eric Sandquist , Marc Pinsonneault

The first paper in this series explored the effects of altering the chemical mixture of the stellar population on an element by element basis on stellar evolutionary tracks and isochrones to the end of the red giant branch. This paper…

We complement our study of alpha/Fe enhanced stellar population models of Lick absorption indices (Thomas et al. 2003) by comparing two sets of alpha/Fe enhanced models. In both models the impact on Lick indices due to alpha/Fe enhancement…

Astrophysics · Physics 2009-11-07 Daniel Thomas , Claudia Maraston

We present the result of our investigation on the impact of the low Solar abundance of Asplund and collaborators (2004) on the derived ages for the oldest star clusters based on isochrone fittings. We have constructed new stellar models and…

Solar and Stellar Astrophysics · Physics 2015-05-19 Sukyoung K. Yi , Yong -Cheol Kim

We present a self-consistent, absolute isochronal age scale for young (< 200 Myr), nearby (< 100 pc) moving groups, which is consistent with recent lithium depletion boundary ages for both the Beta Pic and Tucana-Horologium moving groups.…

Solar and Stellar Astrophysics · Physics 2016-02-03 Cameron P. M. Bell , Eric E. Mamajek , Tim Naylor

This is the first of a series of papers presenting the Modules for Experiments in Stellar Astrophysics (MESA) Isochrones and Stellar Tracks (MIST) project, a new comprehensive set of stellar evolutionary tracks and isochrones computed using…

Solar and Stellar Astrophysics · Physics 2016-06-01 Jieun Choi , Aaron Dotter , Charlie Conroy , Matteo Cantiello , Bill Paxton , Benjamin D. Johnson

We update and expand the MESA Isochrones and Stellar Tracks (MIST) database to include variations in the alpha-capture elements, specifically [alpha/Fe]=-0.2, 0, +0.2, +0.4, and +0.6 for -3 <= [Fe/H] <= +0.5. Variations in [alpha/Fe] are…

Solar and Stellar Astrophysics · Physics 2026-02-26 A Dotter , E Bauer , MJ Park , C Conroy , A Milone , M Joyce , M Cantiello

We present the first models allowing one to explore in a consistent way the influence of changes in the alpha-element-to-iron abundance ratio on the high-resolution spectral properties of evolving stellar populations. The models cover the…

Astrophysics · Physics 2008-01-08 P. Coelho , G. Bruzual , S. Charlot , A. Weiss , B. Barbuy , J. Ferguson

An improved algorithm for interpolating isochrones and isochrone population functions (IPFs), based on the scheme introduced by Bergbusch & VandenBerg (1992, APJS, 81, 163), is described. The computer programs (FORTRAN 77) and the grids of…

Astrophysics · Physics 2009-11-06 Peter A. Bergbusch , Don A. VandenBerg

Recent work has shown that most globular clusters have at least two chemically distinct components, as well as cluster-to-cluster differences in the mean [O/Fe], [Mg/Fe], and [Si/Fe] ratios at similar [Fe/H] values. In order to investigate…

Solar and Stellar Astrophysics · Physics 2015-06-05 Don A. VandenBerg , Peter A. Bergbusch , Aaron Dotter , Jason W. Ferguson , Georges Michaud , Jacques Richer , Charles Proffitt