skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: ORBITAL CIRCULARIZATION OF HOT AND COOL KEPLER ECLIPSING BINARIES

Abstract

The rate of tidal circularization is predicted to be faster for relatively cool stars with convective outer layers, compared to hotter stars with radiative outer layers. Observing this effect is challenging because it requires large and well-characterized samples that include both hot and cool stars. Here we seek evidence of the predicted dependence of circularization upon stellar type, using a sample of 945 eclipsing binaries observed by Kepler . This sample complements earlier studies of this effect, which employed smaller samples of better-characterized stars. For each Kepler binary we measure e cos ω based on the relative timing of the primary and secondary eclipses. We examine the distribution of e cos ω as a function of period for binaries composed of hot stars, cool stars, and mixtures of the two types. At the shortest periods, hot–hot binaries are most likely to be eccentric; for periods shorter than four days, significant eccentricities occur frequently for hot–hot binaries, but not for hot–cool or cool–cool binaries. This is in qualitative agreement with theoretical expectations based on the slower dissipation rates of hot stars. However, the interpretation of our results is complicated by the largely unknown ages and evolutionary states of the stars inmore » our sample.« less

Authors:
;  [1]
  1. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
Publication Date:
OSTI Identifier:
22666208
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 824; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BINARY STARS; COMPARATIVE EVALUATIONS; DISTRIBUTION; ECLIPSE; LAYERS; PLANETS; SATELLITES; STABILITY; STAR EVOLUTION

Citation Formats

Eylen, Vincent Van, Albrecht, Simon, and Winn, Joshua N., E-mail: vincent@phys.au.dk. ORBITAL CIRCULARIZATION OF HOT AND COOL KEPLER ECLIPSING BINARIES. United States: N. p., 2016. Web. doi:10.3847/0004-637X/824/1/15.
Eylen, Vincent Van, Albrecht, Simon, & Winn, Joshua N., E-mail: vincent@phys.au.dk. ORBITAL CIRCULARIZATION OF HOT AND COOL KEPLER ECLIPSING BINARIES. United States. https://doi.org/10.3847/0004-637X/824/1/15
Eylen, Vincent Van, Albrecht, Simon, and Winn, Joshua N., E-mail: vincent@phys.au.dk. 2016. "ORBITAL CIRCULARIZATION OF HOT AND COOL KEPLER ECLIPSING BINARIES". United States. https://doi.org/10.3847/0004-637X/824/1/15.
@article{osti_22666208,
title = {ORBITAL CIRCULARIZATION OF HOT AND COOL KEPLER ECLIPSING BINARIES},
author = {Eylen, Vincent Van and Albrecht, Simon and Winn, Joshua N., E-mail: vincent@phys.au.dk},
abstractNote = {The rate of tidal circularization is predicted to be faster for relatively cool stars with convective outer layers, compared to hotter stars with radiative outer layers. Observing this effect is challenging because it requires large and well-characterized samples that include both hot and cool stars. Here we seek evidence of the predicted dependence of circularization upon stellar type, using a sample of 945 eclipsing binaries observed by Kepler . This sample complements earlier studies of this effect, which employed smaller samples of better-characterized stars. For each Kepler binary we measure e cos ω based on the relative timing of the primary and secondary eclipses. We examine the distribution of e cos ω as a function of period for binaries composed of hot stars, cool stars, and mixtures of the two types. At the shortest periods, hot–hot binaries are most likely to be eccentric; for periods shorter than four days, significant eccentricities occur frequently for hot–hot binaries, but not for hot–cool or cool–cool binaries. This is in qualitative agreement with theoretical expectations based on the slower dissipation rates of hot stars. However, the interpretation of our results is complicated by the largely unknown ages and evolutionary states of the stars in our sample.},
doi = {10.3847/0004-637X/824/1/15},
url = {https://www.osti.gov/biblio/22666208}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 824,
place = {United States},
year = {Fri Jun 10 00:00:00 EDT 2016},
month = {Fri Jun 10 00:00:00 EDT 2016}
}