Welcome to the SDSS WDMS binary catalogue!
The SDSS WDMS binary catalogue is a data base that contains all kind of information for the more than 3200 White Dwarf-Main Sequence binaries identified within the Sloan Digital Sky Survey. This user friendly data base is open for the general public, however permission to update the data base will be restricted to our team.
If you want to get all available information from a specific object you should click on 'Search by object'. If you want to get a list of objects for a given query please click on 'Search by parameter'. If you want to run a query with SQL language by yourself please click on 'Search SQL query'.
For any questions and/or comments please write to Alberto Rebassa-Mansergas: alberto.rebassa(at)gmail.com
Note on the stellar parameters: we are updating our fitting/decomposition routine for using M-dwarf models to fit our WDMS binary spectra. This will allow us to obtain M-dwarf effective temperatures. Age estimates will also be obtained for our systems. Using evolutionary models for low-mass stars at a given age and effective temperature, we will also calculate the mass, radius and luminosity of our secondary stars. Until this work is finished, the values are set to 0 in the current version of the online SDSS WDMS binary catalogue.
Acknowledgement: If you make use of this web site please cite Rebassa-Mansergas et al. 2012 MNRAS 419 806R
We are in the process of updating the website with the new identifications. 7/06/2013 The catalogue has been updated and includes now the latest version of 2316 SDSS WDMS from DR8 SDSS WDMS DR8
14/11/2012 SDSSJ135523.92+085645.4 has been added. Hot WD plus possible brown dwarf discovered by Badenes et al. (2012). 20/07/2012 SDSSJ014349.22+002130.0 has been excluded from the list. Blue excess comes from nearby QSO rather than from a real white dwarf. 24/07/2012 The eclipsing WD/dM SDSSJ013851.54-001621.6 has been added to the list. 24/07/2012 SDSSJ144335.19+004005.9 has been excluded. Its an M dwarf/M dwarf eclipsing binary (~1 day orbital period).
PCEBs from SDSS
WDMS binaries were initially main sequence binaries in which the more massive star evolved through the giant phase and became a white dwarf. In the majority of cases the initial separation of the main sequence binary is wide enough to allow the evolution of both stars as if they were single. A small fraction is believed to undergo a phase of dynamically unstable mass transfer once the more massive star is on the giant branch or the asymptotic giant branch. As a consequence of this mass-transfer the envelope of the giant will engulf its core and the companion star, i.e. the system is entering a common envelope phase (CE). Friction inside this envelope causes a rapid decrease of the binary separation. Henceforth orbital energy and angular momentum are extracted from the binary orbit and lead to the ejection of the envelope, exposing a post-common-envelope binary (PCEB). After the ejection of the envelope, PCEBs evolve to shorter orbital periods through angular momentum loss via magnetic braking and/or through the emission of gravitational waves.
Population synthesis models have been developed for a variety of binary stars undergoing CE evolution. However, the theoretical understanding of both CE evolution and magnetic braking has been poorly constrained by observations, and progress on this front is most likely to arise from the analysis of a large sample of PCEBs that are well-understood in terms of their stellar components. WDMS binaries appear most promising in that respect, as their stellar components are relatively simple, and the SDSS has increased dramatically the number of WDMS binaries available for detailed follow-up studies.
During the last years we have dedicated our efforts towards identifying a large sample of PCEBs, determining their stellar parameters, and measuring their orbital periods to provide the much needed observational constraints for theories of compact binary evolution.