TexasScholarWorks
    • Login
    • Submit
    View Item 
    •   Repository Home
    • UT Faculty/Researcher Works
    • UT Faculty/Researcher Works
    • View Item
    • Repository Home
    • UT Faculty/Researcher Works
    • UT Faculty/Researcher Works
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Two New Tidally Distorted White Dwarfs

    Thumbnail
    View/Open
    2012_04_twonewtidally.pdf (950.3Kb)
    Date
    2012-04
    Author
    Hermes, J. J.
    Kilic, Mukremin
    Brown, Warren R.
    Montgomery, Michael H.
    Winget, D. E.
    Share
     Facebook
     Twitter
     LinkedIn
    Metadata
    Show full item record
    Abstract
    We identify two new tidally distorted white dwarfs (WDs), SDSS J174140.49+652638.7 and J211921.96-001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, <= 0.2 M-circle dot)WDs in short-period, detached binary systems. High-speed photometric observations obtained at the McDonald Observatory reveal ellipsoidal variations and Doppler beaming in both systems; J1741, with a minimum companion mass of 1.1 M-circle dot, has one of the strongest Doppler beaming signals ever observed in a binary system (0.59% +/- 0.06% amplitude). We use the observed ellipsoidal variations to constrain the radius of each WD. For J1741, the star's radius must exceed 0.074R(circle dot). For J2119, the radius exceeds 0.10R(circle dot). These indirect radius measurements are comparable to the radius measurements for the bloated WD companions to A-stars found by the Kepler spacecraft, and they constitute some of the largest radii inferred for any WD. Surprisingly, J1741 also appears to show a 0.23% +/- 0.06% reflection effect, and we discuss possible sources for this excess heating. Both J1741 and J2119 are strong gravitational wave sources, and the time-of-minimum of the ellipsoidal variations can be used to detect the orbital period decay. This may be possible on a timescale of a decade or less.
    Department
    McDonald Observatory
    Subject
    binaries: close
    galaxy: stellar content
    stars: individual (sdss
    j174140.49+652638.7, sdss j211921.96-001825.8)
    stars: neutron
    stars:
    variables: general
    white dwarfs
    binary nltt 11748
    eclipsing binary
    system
    helium
    stars
    discovery
    kepler
    variability
    evolution
    companion
    astronomy & astrophysics
    URI
    http://hdl.handle.net/2152/34904
    Citation
    Hermes, J. J., Mukremin Kilic, Warren R. Brown, M. H. Montgomery, and D. E. Winget. "Two new tidally distorted white dwarfs." The Astrophysical Journal, Vol. 749, No. 1 (Apr., 2012): 42.
    Collections
    • UT Faculty/Researcher Works

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin

     

     

    Browse

    Entire RepositoryCommunities & CollectionsDate IssuedAuthorsTitlesSubjectsDepartmentsThis CollectionDate IssuedAuthorsTitlesSubjectsDepartments

    My Account

    Login

    Statistics

    View Usage Statistics

    Information

    About Contact Policies Getting Started Glossary Help FAQs

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin