Multiband light-curve analysis of the 40.5-min period eclipsing double-degenerate binary SDSS J082239.54+304857.19
Abstract
We present the Apache Point Observatory BG40 broad-band and simultaneous Gemini r-band and i-band high-speed follow-up photometry observations and analysis of the 40.5-min period eclipsing detached double-degenerate binary SDSS J082239.54+304857.19. Our APO data spans over 318 d and includes 13 primary eclipses, from which we precisely measure the system's orbital period and improve the time of mid-eclipse measurement. We fit the light curves for each filter individually and show that this system contains a low-mass DA white dwarf with radius RA = 0.031 ± 0.006 R⊙ and a RB = 0.013 ± 0.005 R⊙ companion at an inclination of i = 87.7 ± 0.2○. We use the best-fitting eclipsing light curve model to estimate the temperature of the secondary star as Teff = 5200 ± 100 K. Finally, while we do not record significant offsets to the expected time of mid-eclipse caused by the emission of gravitational waves with our 1-yr baseline, we show that a 3σ significant measurement of the orbital decay due to gravitational waves will be possible in 2023, at which point the eclipse will occur about 8 s earlier than expected.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2021
- DOI:
- 10.1093/mnras/staa3571
- arXiv:
- arXiv:2011.11748
- Bibcode:
- 2021MNRAS.500.5098K
- Keywords:
-
- binaries: eclipsing;
- stars: individual: J082239.54+304857.19;
- stars: individual: J0822+3048;
- white dwarfs;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 8 pages, 8 figures, 2 tables. Accepted for publication in MNRAS