Orbital Decay in a 20 Minute Orbital Period Detached Binary with a Hydrogen-poor Low-mass White Dwarf

DOI: 
10.3847/2041-8213/ab53e5
Publication date: 
01/11/2019
Main author: 
Burdge, Kevin B.
IAA authors: 
Claret, Antonio
Authors: 
Burdge, Kevin B.;Fuller, Jim;Phinney, E. Sterl;van Roestel, Jan;Claret, Antonio;Cukanovaite, Elena;Gentile Fusillo, Nicola Pietro;Coughlin, Michael W.;Kaplan, David L.;Kupfer, Thomas;Tremblay, Pier-Emmanuel;Dekany, Richard G.;Duev, Dmitry A.;Feeney, Michael;Riddle, Reed;Kulkarni, S. R.;Prince, Thomas A.
Journal: 
The Astrophysical Journal Letters
Refereed: 
Yes
Publication type: 
Article
Volume: 
886
Pages: 
L12
Abstract: 
We report the discovery of a detached double white dwarf binary with an orbital period of ≈20.6 minutes, PTF J053332.05+020911.6. The visible object in this binary, PTF J0533+0209B, is a ≈0.17 M <SUB>☉</SUB> mass white dwarf with a helium-dominated atmosphere containing traces of hydrogen. This object exhibits ellipsoidal variations due to tidal deformation, and is the visible component in a single-lined spectroscopic binary with a velocity semi-amplitude of K <SUB> B </SUB> = 618.7 ± 6.9 km s<SUP>−1</SUP>. We have detected significant orbital decay due to the emission of gravitational radiation, and we expect that the Laser Interferometer Space Antenna (LISA) will detect this system with a signal to noise of {8.4}<SUB>-3.0</SUB><SUP>+4.2</SUP> after four years of operation. Because this system already has a well-determined orbital period, radial velocity semi-amplitude, temperature, atmospheric composition, surface gravity, and orbital decay rate, a LISA signal will help fully constrain the properties of this system by providing a direct measurement of its inclination. Thus, this binary demonstrates the synergy between electromagnetic and gravitational radiation for constraining the physical properties of an astrophysical object.
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077740412&doi=10.3847%2f2041-8213%2fab53e5&partnerID=40&md5=b503e9e1c136bbc4fbded2da049cea6d
ADS Bibcode: 
2019ApJ...886L..12B
Keywords: 
White dwarf stars;Gravitational wave sources;Compact binary stars;Detached binary stars;Ellipsoidal variable stars;Spectroscopic binary stars;Relativistic binary stars;High energy astrophysics;Astrophysics - Solar and Stellar Astrophysics;Astrophysics - High Energy Astrophysical Phenomena