The Ultra Compact sdB+WD binary CD -30 11223
Abstract
We have recently discovered that CD -30 11223 is a binary composed of a white dwarf orbiting a subdwarf of B spectral type in only 1.2 hours. This is by far the shortest orbital period of any sdB+WD binary. The orbital separation of only 0.6 solar radii implies that the subdwarf is very close to fill its Roche-lobe, making this system an optimal candidate for observations at X-ray energies. X-ray observations can give information on properties of the white dwarf unaccessible in other bands, which are particularly interesting given the possibility that this close binary be the progenitor of a SN Ia via the so-called sub-Chandrasekhar double-detonation scenario.
- Publication:
-
XMM-Newton Proposal
- Pub Date:
- October 2012
- Bibcode:
- 2012xmm..prop...43H
- Keywords:
-
- White Dwarf Binaries;
- Neutron Star Binaries;
- Cataclysmic Variables;
- ULXs;
- Black Holes;
- CD -30 11223