14 new eclipsing white dwarf plus main-sequence binaries from the SDSS and Catalina surveys
Abstract
We report on the search for new eclipsing white dwarf plus main-sequence (WDMS) binaries in the light curves of the Catalina surveys. We use a colour-selected list of almost 2000 candidate WDMS systems from the Sloan Digital Sky Survey, specifically designed to identify WDMS systems with cool white dwarfs and/or early M-type main-sequence stars. We identify a total of 17 eclipsing systems, 14 of which are new discoveries. We also find three candidate eclipsing systems, two main-sequence eclipsing binaries and 22 non-eclipsing close binaries. Our newly discovered systems generally have optical fluxes dominated by the main-sequence components, which have earlier spectral types than the majority of previously discovered eclipsing systems. We find a large number of ellipsoidally variable binaries with similar periods, near 4 h, and spectral types M2-3, which are very close to Roche lobe filling. We also find that the fraction of eclipsing systems is lower than found in previous studies and likely reflects a lower close binary fraction among WDMS binaries with early M-type main-sequence stars due to their enhanced angular momentum loss compared to fully convective late M-type stars, hence causing them to become cataclysmic variables quicker and disappear from the WDMS sample. Our systems bring the total number of known detached, eclipsing WDMS binaries to 71.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2015
- DOI:
- 10.1093/mnras/stv382
- arXiv:
- arXiv:1502.05723
- Bibcode:
- 2015MNRAS.449.2194P
- Keywords:
-
- binaries: close;
- binaries: eclipsing;
- stars: low mass;
- white dwarfs;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 12 pages, 9 figures, 4 tables. Accepted for publication in MNRAS