Hot subdwarf binaries from the MUCHFUSS project Analysis of 12 new systems and a study of the short-period binary population

• Published in: Astronomy and astrophysics (Berlin) Vol. 576; p. A44
• Main Authors: Kupfer, T, Geier, S, Heber, U, Ostensen, R H, Barlow, B N, Maxted, P F L, Heuser, C, Schaffenroth, V, Gansicke, B T
• Format: Journal Article
• Language: English
• Published: 01.04.2015
• Subjects: Binary stars; Binary systems; Brown dwarf stars; Neutron stars; Progenitors (astrophysics); Stars; Subdwarf stars; White dwarf stars
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201425213

The project Massive Unseen Companions to Hot Faint Under-luminous Stars from SDSS (MUCHFUSS) aims at finding hot sub-dwarf stars with massive compact companions like massive white dwarfs, neutron stars, or stellar-mass black holes. We present orbital and atmospheric parameters and put constraints on the nature of the companions of 12 close hot sub-dwarf B star (sdB) binaries found in the course of the MUCHFUSS project. We identified 16 systems where the dM companion will fill its Roche Lobe within a Hubble time and will evolve into a cataclysmic variable; two of them will have a brown dwarf as donor star. Twelve systems with confirmed white dwarf companions will merge within a Hubble time, two of them having a mass ratio to evolve into a stable AM Cvn-type binary and another two which are potential supernova Ia progenitor systems. The remaining eight systems will most likely merge and form RCrB stars or massive C/O white dwarfs depending on the structure of the white dwarf companion.