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Title: A Model of the Pulsating Extremely Low-mass White Dwarf Precursor WASP 0247–25B

Abstract

We present an analysis of the evolutionary and pulsation properties of the extremely low-mass white dwarf precursor (B) component of the double-lined eclipsing system WASP 0247−25. Given that the fundamental parameters of that star have been obtained previously at a unique level of precision, WASP 0247−25B represents the ideal case for testing evolutionary models of this newly found category of pulsators. Taking into account the known constraints on the mass, orbital period, effective temperature, surface gravity, and atmospheric composition, we present a model that is compatible with these constraints and show pulsation modes that have periods very close to the observed values. Importantly, these modes are predicted to be excited. Although the overall consistency remains perfectible, the observable properties of WASP 0247−25B are closely reproduced. A key ingredient of our binary evolutionary models is represented by rotational mixing as the main competitor against gravitational settling. Depending on assumptions made about the values of the degree index ℓ for the observed pulsation modes, we found three possible seismic solutions. We discuss two tests, rotational splitting and multicolor photometry, that should readily identify the modes and discriminate between these solutions. However, this will require improved temporal resolution and higher S/N observations, whichmore » are currently unavailable.« less

Authors:
 [1];  [2];  [3]
  1. Center for Gravitation, Cosmology, and Astrophysics, Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201 (United States)
  2. Département de Physique, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7 (Canada)
  3. Dr. Karl Remeis-Observatory and ECAP, Astronomical Institute, Friedrich-Alexander University Erlangen-Nürnberg, Sternwartstr. 7, D-96049 Bamberg (Germany)
Publication Date:
OSTI Identifier:
22679793
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 847; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; COMPUTERIZED SIMULATION; ECLIPSE; GRAVITATION; INDEXES; MASS; MIXING; PHOTOMETRY; PRECURSOR; PULSATIONS; RESOLUTION; STAR EVOLUTION; SURFACES; WHITE DWARF STARS

Citation Formats

Istrate, A. G., Fontaine, G., and Heuser, C., E-mail: istrate@uwm.edu. A Model of the Pulsating Extremely Low-mass White Dwarf Precursor WASP 0247–25B. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA8958.
Istrate, A. G., Fontaine, G., & Heuser, C., E-mail: istrate@uwm.edu. A Model of the Pulsating Extremely Low-mass White Dwarf Precursor WASP 0247–25B. United States. doi:10.3847/1538-4357/AA8958.
Istrate, A. G., Fontaine, G., and Heuser, C., E-mail: istrate@uwm.edu. Sun . "A Model of the Pulsating Extremely Low-mass White Dwarf Precursor WASP 0247–25B". United States. doi:10.3847/1538-4357/AA8958.
@article{osti_22679793,
title = {A Model of the Pulsating Extremely Low-mass White Dwarf Precursor WASP 0247–25B},
author = {Istrate, A. G. and Fontaine, G. and Heuser, C., E-mail: istrate@uwm.edu},
abstractNote = {We present an analysis of the evolutionary and pulsation properties of the extremely low-mass white dwarf precursor (B) component of the double-lined eclipsing system WASP 0247−25. Given that the fundamental parameters of that star have been obtained previously at a unique level of precision, WASP 0247−25B represents the ideal case for testing evolutionary models of this newly found category of pulsators. Taking into account the known constraints on the mass, orbital period, effective temperature, surface gravity, and atmospheric composition, we present a model that is compatible with these constraints and show pulsation modes that have periods very close to the observed values. Importantly, these modes are predicted to be excited. Although the overall consistency remains perfectible, the observable properties of WASP 0247−25B are closely reproduced. A key ingredient of our binary evolutionary models is represented by rotational mixing as the main competitor against gravitational settling. Depending on assumptions made about the values of the degree index ℓ for the observed pulsation modes, we found three possible seismic solutions. We discuss two tests, rotational splitting and multicolor photometry, that should readily identify the modes and discriminate between these solutions. However, this will require improved temporal resolution and higher S/N observations, which are currently unavailable.},
doi = {10.3847/1538-4357/AA8958},
journal = {Astrophysical Journal},
number = 2,
volume = 847,
place = {United States},
year = {Sun Oct 01 00:00:00 EDT 2017},
month = {Sun Oct 01 00:00:00 EDT 2017}
}