2011/03/11 by Mukremin Kilic, Warren R. Brown, S. J. Kenyon +6
Physics and Astronomy · #Astronomy and Astrophysical Research #Binary star #Ephemeris #Gravitational wave #Orbital elements #Orbital inclination #Orbital period #Photometry (optics) #Pulsar #Pulsars and Gravitational Waves Research #Radial velocity #Stellar, planetary, and galactic studies #White dwarf #astro-ph.GA
paper · pdf · doi:10.1111/j.1745-3933.2011.01044.x
MNRAS Letters, in press
arxiv created 2011/03/11 · openalex publication_date 2011/03/24 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We identify SDSSJ010657.39−100003.3 (hereafter J0106−1000) as the shortest period detached binary white dwarf (WD) system currently known. We targeted J0106−1000 as part of our radial velocity programme to search for companions around known extremely low-mass (ELM; ∼0.2M⊙) WDs using the 6.5-m Multiple Mirror Telescope. We detect peak-to-peak radial velocity variations of 740kms−1 with an orbital period of 39.1min. The mass function and optical photometry rule out a main-sequence star companion. Follow-up high-speed photometric observations obtained at the McDonald 2.1-m telescope reveal ellipsoidal variations from the distorted primary but no eclipses. This is the first example of a tidally distorted WD. Modelling the light curve, we constrain the inclination angle of the system to be 67°± 13°. J0106−1000 contains a pair of WDs (0.17M⊙ primary + 0.43M⊙ invisible secondary) at a separation of 0.32R⊙. The two WDs will merge in 37Myr and most likely form a core He-burning single subdwarf star. J0106−1000 is the shortest time-scale merger system currently known. The gravitational wave strain from J0106−1000 is at the detection limit of the Laser Interferometer Space Antenna (LISA). However, accurate ephemeris and orbital period measurements may enable LISA to detect J0106−1000 above the Galactic background noise.