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Related papers: Composite hot-subdwarf binaries -- I. The spectros…

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Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of…

Solar and Stellar Astrophysics · Physics 2015-06-15 Brad N. Barlow , Sandra E. Liss , Richard A. Wade , Elizabeth M. Green

In this study, we concentrate on the formation and evolution of hot subdwarfs binaries through the stable Roche lobe overflow (RLOF) channel of intermediate-mass binaries. We aim at setting out the properties of hot subdwarfs and their…

Solar and Stellar Astrophysics · Physics 2009-08-24 S. Yu , L. Li

The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…

Astrophysics · Physics 2008-04-09 S. Geier , C. Karl , H. Edelmann , U. Heber , R. Napiwotzki

The current theory predicts that hot subdwarf binaries are produced from evolved low-mass binaries that have undergone mass transfer and drastic mass loss during either a common envelope phase or a stable Roche lobe overflow while on the…

Solar and Stellar Astrophysics · Physics 2022-12-14 Murat Uzundag , Matias I. Jones , Maja Vučković , Joris Vos , Alexey Bobrick , Claudia Paladini

222 hot subdwarf stars were identified with LAMOST DR8 spectra, among which 131 stars show composite spectra and have been decomposed, while 91 stars present single-lined spectra. Atmospheric parameters of all sample stars were obtained by…

Solar and Stellar Astrophysics · Physics 2023-01-25 Zhenxin Lei , Ruijie He , Peter Nemeth , Joris Vos , Xuan Zou , Ke Hu , Huaping Xiao , Huahui Yan , Jingkun Zhao

Hot subdwarf B (sdB) stars are post-main-sequence stars of high temperature and gravity. Approximately 30$\%$ of sdBs exhibit stable pressure and/or gravity-mode pulsations, which can be used via the timing method to test for companion…

Solar and Stellar Astrophysics · Physics 2025-08-05 Tomomi Otani , A. S. Baran , Lindsay C. Spence , Ted von Hippel , E. Lynum-Lozano , Julia. M. Clark

The predicted orbital-period distribution of the subdwarf-B (sdB) population is bi-modal with a peak at short (< 10 days) and long (> 500 days) periods. Observationally, many short-period sdB systems are known, but only few wide sdB…

Solar and Stellar Astrophysics · Physics 2017-09-20 Joris Vos , Roy H. Østensen , Maja Vuckovic , Hans Van Winckel

We report the discovery of the first hot subdwarf B (sdB) star with a massive compact companion in a wide ($P=892.5\pm60.2\,{\rm d}$) binary system. It was discovered based on an astrometric binary solution provided by the Gaia mission Data…

Solar and Stellar Astrophysics · Physics 2023-08-30 S. Geier , M. Dorsch , H. Dawson , I. Pelisoli , J. Munday , T. R. Marsh , V. Schaffenroth , U. Heber

There are 23 long-period binary systems discovered to date that contain a B-type hot subdwarf(sdB) whose orbital parameters have been fully solved. They evolve into O-type subdwarfs (sdO) once the helium burning transitions from the core to…

Solar and Stellar Astrophysics · Physics 2022-02-09 Francisco Molina , Joris Vos , Péter Németh , Roy Østensen , Maja Vučković , Andrew Tkachenko , Hans van Winckel

We report the discovery of the first short period binary in which a hot subdwarf star (sdOB) fills its Roche lobe and started mass transfer to its companion. The object was discovered as part of a dedicated high-cadence survey of the…

We present the results of a 3.5 year long campaign to measure orbital periods of subdwarf B (sdB) star binaries. We directly compare our observed orbital period distribution with that predicted by using binary population synthesis. Up to…

Astrophysics · Physics 2009-11-10 L. Morales-Rueda , P. F. L. Maxted , T. R. Marsh

Hot subdwarf stars (sdO/Bs) are the stripped cores of red giants located at the bluest extension of the horizontal branch. They constitute the dominant population of UV-bright stars in old stellar environments and are most likely formed by…

Solar and Stellar Astrophysics · Physics 2016-09-07 S. Geier , T. Kupfer , V. Schaffenroth , U. Heber , the MUCHFUSS collaboration

Subdwarf B (sdB) stars are thought to be core helium burning stars with low mass hydrogen envelopes. In recent years it has become clear that many sdB stars lose their hydrogen through interaction with a binary companion and continue to…

Astrophysics · Physics 2009-11-07 L. Morales-Rueda , P. F. L. Maxted , T. R. Marsh , R. C. North , U. Heber

Subdwarf B (sdB) stars are thought to be helium burning stars with low mass hydrogen envelopes. Several evolutionary paths have been proposed to explain the formation of these systems. One of these scenarios is the evolution of the sdB…

Astrophysics · Physics 2007-05-23 L. Morales-Rueda , P. F. L. Maxted , T. R. Marsh , R. C. North

Hot subdwarf B stars (sdBs) in close binary systems are assumed to be formed via common envelope ejection. According to theoretical models, the amount of energy and angular momentum deposited in the common envelope scales with the mass of…

Solar and Stellar Astrophysics · Physics 2015-05-27 S. Geier , R. Napiwotzki , U. Heber , G. Nelemans

Hot subdwarf B stars (sdBs) are core helium-burning stars located on the extreme horizontal branch. About half of the known sdB stars are found in close binaries. Their short orbital periods of 1.2 h to a few days suggest that they are post…

Solar and Stellar Astrophysics · Physics 2014-05-08 V. Schaffenroth , S. Geier , U. Heber , T. Kupfer , E. Ziegerer , C. Heuser , L. Classen , O. Cordes

Hot subdwarfs (sdBs) are core helium-burning stars, which lost almost their entire hydrogen envelope in the red-giant phase. Since a high fraction of those stars are in close binary systems, common envelope ejection is an important…

Solar and Stellar Astrophysics · Physics 2015-02-02 S. Geier , T. Kupfer , U. Heber , B. N. Barlow , P. F. L. Maxted , C. Heuser , V. Schaffenroth , E. Ziegerer , R. H. Østensen , B. T. Gänsicke

Subluminous B stars (sdBs) form the extremely hot end of the horizontal branch and are therefore related to the blue horizontal branch (BHB) stars. While the rotational properties of BHB stars have been investigated extensively, studies of…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. Geier , U. Heber

The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding hot subdwarf stars (sdBs) with massive compact companions such as white dwarfs, neutron stars, or stellar-mass black holes. In a…

Solar and Stellar Astrophysics · Physics 2015-06-18 S. Geier , R. H. Oestensen , U. Heber , T. Kupfer , P. F. L. Maxted , B. N. Barlow , M. Vuckovic , A. Tillich , S. Mueller , H. Edelmann , L. Classen , A. F. McLeod

In the last decade or so, there have been numerous searches for hot subdwarfs in close binaries. There has been little to no attention paid to wide binaries however. The advantages of understanding these systems can be many. The stars can…

Solar and Stellar Astrophysics · Physics 2015-05-18 Simon J. O'Toole