Preliminary Constraints on 12C(alpha,gamma)16O from White Dwarf Seismology

Abstract

For many years, astronomers have promised that the study of pulsating white dwarfs would ultimately lead to useful information about the physics of matter under extreme conditions of temperature and pressure. In this paper we finally make good on that promise. Using observational data from the Whole Earth Telescope and a new analysis method employing a genetic algorithm, we empirically determine that the central oxygen abundance in the helium-atmosphere variable white dwarf GD 358 is 84+/-3 percent. We use this value to place preliminary constraints on the 12C(alpha,gamma)16O nuclear reaction cross-section. More precise constraints will be possible with additional detailed simulations. We also show that the pulsation modes of our best-fit model probe down to the inner few percent of the stellar mass. We demonstrate the feasibility of reconstructing the internal chemical profiles of white dwarfs from asteroseismological data, and find an oxygen profile for GD 358 that is qualitatively similar to recent theoretical calculations.

Accepted for publication in the Astrophysical Journal, 7 pages, 6 figures, 2 tables, uses emulateapj5.sty

Cited by in corpus (30)

• Evolutionary and pulsational properties of white dwarf stars
• Constraints from gravitational wave detections of binary black hole mergers on the ${}^{12}\mathrm{C}{\left(\alpha ,\gamma \right)}^{16}\mathrm{O}$ rate
• The chemical composition of White Dwarfs as a test of convective efficiency during core He-burning
• On the Thermonuclear Runaway in Type Ia Supernovae: How to run away?
• Stellar Structure Modeling using a Parallel Genetic Algorithm for Objective Global Optimization
• Measuring ^{12}C(&alpha,&gamma)^{16}O from White Dwarf Asteroseismology
• Gravitational Settling of ^{22}Ne in Liquid White Dwarf Interiors--Cooling and Seismological Effects
• Secondary Parameters of Type Ia Supernova Light Curves
• The core/envelope symmetry in pulsating stars
• Calibration of White Dwarf cooling sequences: theoretical uncertainty
• White Dwarf Asteroseismology and the ^12C(alpha,gamma)^16O Rate
• The Everchanging Pulsating White Dwarf GD358
• Two white dwarfs with oxygen-rich atmospheres
• Carbon-Oxygen Phase Separation in MESA White Dwarf Models
• A deeper understanding of white dwarf interiors
• White Dwarf cooling Sequences, II: luminosity functions
• Probing the core and envelope structure of DBV white dwarfs
• Asteroseismic constraints on diffusion in WD envelopes
• GD358: three decades of observations for the in-depth asteroseismology of a DBV star
• The double-layered chemical structure in DB white dwarfs
• The asteroseismological potential of the pulsating DB white dwarf stars CBS 114 and PG 1456+103
• Time dependent diffusion in pulsating white dwarf stars: Asteroseismology of G117-B15A
• Magnetic field breakout from white dwarf crystallization dynamos
• On Trapped Modes In Variable White Dwarfs As Probes Of The ${}^{12}$C($\alpha ,\gamma$)${}^{16}$O Reaction Rate
• The rate of period change in pulsating DB white dwarf stars
• Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with {\it TESS}: III. Asteroseismology of the DBV star GD 358
• From Theory to Observations and viceversa: theoretical uncertainties and observational constraints
• Life Products of Stars
• Lessons for Asteroseismology from White Dwarf Stars
• On the possibility of using seismic probes to study the core composition in pulsating white dwarfs