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Physical Sciences and Mathematics Commons

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Stars, Interstellar Medium and the Galaxy

Dartmouth Scholarship

2013

Mass

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

A Bayesian Approach To Deriving Ages Of Individual Field White Dwarfs, Erin M. O'Malley, Ted Von Hippel, David A. Van Dyk Aug 2013

A Bayesian Approach To Deriving Ages Of Individual Field White Dwarfs, Erin M. O'Malley, Ted Von Hippel, David A. Van Dyk

Dartmouth Scholarship

We apply a self-consistent and robust Bayesian statistical approach to determine the ages, distances, and zero-age main sequence (ZAMS) masses of 28 field DA white dwarfs (WDs) with ages of approximately 4-8 Gyr. Our technique requires only quality optical and near-infrared photometry to derive ages with <15% uncertainties, generally with little sensitivity to our choice of modern initial-final mass relation. We find that age, distance, and ZAMS mass are correlated in a manner that is too complex to be captured by traditional error propagation techniques. We further find that the posterior distributions of age are often asymmetric, indicating that the standard approach to deriving WD ages can yield misleading results.


The Interior Structure Constants As An Age Diagnostic For Low-Mass, Pre-Main-Sequence Detached Eclipsing Binary Stars, Gregory A. Feiden, Aaron Dotter Feb 2013

The Interior Structure Constants As An Age Diagnostic For Low-Mass, Pre-Main-Sequence Detached Eclipsing Binary Stars, Gregory A. Feiden, Aaron Dotter

Dartmouth Scholarship

We propose a novel method for determining the ages of low-mass, pre-main-sequence stellar systems using the apsidal motion of low-mass detached eclipsing binaries. The apsidal motion of a binary system with an eccentric orbit provides information regarding the interior structure constants of the individual stars. These constants are related to the normalized stellar interior density distribution and can be extracted from the predictions of stellar evolution models. We demonstrate that low-mass, pre-main-sequence stars undergoing radiative core contraction display rapidly changing interior structure constants (greater than 5% per 10 Myr) that, when combined with observational determinations of the interior structure constants …