Results 21 to 30 of about 3,864 (175)

Gamma Cas Stars as Be+White Dwarf Binary Systems

The Astrophysical Journal Letters, 2022
The origin of the bright and hard X-ray emission flux among the γ Cas subgroup of B-emission line (Be) stars may be caused by gas accretion onto an orbiting white dwarf (WD) companion.
Douglas R. Gies, Luqian Wang, Robert Klement   +2 more
doaj   +1 more source

New Subdwarf B Star Periods [PDF]

, 2003
4 pages, 2 figures. Uses CRCKAPB.sty. To appear in the Proceedings of the XIII European Workshop on White Dwarfs. NATO Science Series II, Kluwer Academic Publishers.
Morales-Rueda, L., Maxted, P. F. L., Marsh, T. R., North, R. C.   +3 more
openaire   +2 more sources

The origin of subdwarf B stars - II [PDF]

Monthly Notices of the Royal Astronomical Society, 2003
We have carried out a detailed binary population synthesis (BPS) study of the formation of subdwarf B (sdB) stars and related objects (sdO, sdOB stars) using the latest version of the BPS code developed by Han and co-workers. We systematically investigate the importance of the five main evolutionary channels in which the sdB stars form after one or two
Han, Z, Podsiadlowski, P, Maxted, P, Marsh, T   +3 more
openaire   +1 more source

Gravitational settling in pulsating subdwarf B stars and their progenitors [PDF]

, 2009
Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short
A. A. Thoul, Bahcall, Bahcall, Böhm-Vitense, C. Aerts, Cassisi, Caughlan, Charpinet, Charpinet, Chen, Chieffi, Christensen-Dalsgaard, D'Cruz, Dearborn, Dupret, E. Glebbeek, Eggleton, Eggleton, Eggleton, Eggleton, Eldridge, Ferguson, Fontaine, Fontaine, G. Nelemans, Green, Haili Hu, Han, Heber, Herwig, Hu, Hu, Hu, Iglesias, Itoh, Itoh, Jeffery, Jeffery, Kilkenny, M.-A. Dupret, Maxted, Michaud, Michaud, Michaud, Michaud, Mocák, Morales-Rueda, O'Toole, Paquette, Piersanti, Pols, Pols, Pols, R. J. Stancliffe, Reimers, Richard, Richard, Rogers, Rood, Saffer, Schlattl, Schröder, Schröder, Scuflaire, Serenelli, Stancliffe, Stancliffe, Sweigart, Thoul, Turcotte, Unglaub, Vink   +71 more
core   +4 more sources

Physical parameters for subdwarf B stars with composite spectra [PDF]

Astronomy & Astrophysics, 2002
For many years, the evolutionary origins of subdwarf B stars remained a mystery. Observations of sdB stars with composite spectra and theoretical considerations suggested that binary star evolution should play a major role, but proof that a large fraction are binaries has taken a decade to establish.
R. Aznar Cuadrado, C. S. Jeffery
openaire   +2 more sources

Whole Earth Telescope observations of the pulsating subdwarf B star PG 0014+067 [PDF]

, 2006
PG 0014+067 is one of the most promising pulsating subdwarf B stars for seismic analysis, as it has a rich pulsation spectrum. The richness of its pulsations, however, poses a fundamental challenge to understanding the pulsations of these stars, as the ...
Baran, A., Bognár, Zs, Bronowska, A., Castanheira, B. G., Chen, C.-W., Chen, W. P., Childers, D., Csubry, Z., Fraga, L., Handler, G., Hsiao, W.-S., Janulis, R., Jiang, X. J., Kawaler, S. D., Kepler, S. O., Kim, S.-L., Klumpe, E. W., Lee, H.-T., Lorenz, D., Moskalik, P., Mullally, F., Ogloza, W., Oreiro, R., O’Brien, M. S., O’Toole, S., Paparó, M., Provencal, J. L., Reed, M. D., Riddle, R., Sanchawala, K., Shipman, H. L., Silvotti, R., Siwak, Michał, Steininger, B., Sullivan, D. J., Sódor, Á, Terndrup, D. M., Vauclair, G., Vučković, M., Wilkat, V., Wood, M. A., Zhou, A.-Y., Zoła, Stanisław, Østensen, R.   +43 more
core   +2 more sources

In Pursuit of the Least Luminous Galaxies

Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010
The dwarf galaxy companions to the Milky Way are unique cosmological laboratories. With luminosities as low as 10−7LMW, they inhabit the lowest mass dark matter halos known to host stars and are presently the most direct tracers of the distribution, mass spectrum, and clustering scale of dark matter.
Beth Willman, Regina Schulte-Ladbeck
wiley   +1 more source

Mass Distribution for Single-lined Hot Subdwarf Stars in LAMOST

The Astrophysical Journal, 2023
Masses for 664 single-lined hot subdwarf stars identified in LAMOST were calculated by comparing synthetic fluxes from spectral energy distribution with observed fluxes from a Virtual Observatory service.
Zhenxin Lei, Ruijie He, Péter Németh, Xuan Zou, Huaping Xiao, Yong Yang, Jingkun Zhao   +6 more
doaj   +1 more source

Detection of pulsations in three subdwarf B stars [PDF]

Astronomy & Astrophysics, 2001
We report the detection of short period oscillations in the sdB stars HS 0815+4243, HS 2149+0847 and HS 2201+2610 from time-series photometry made at the Nordic Optical Telescope (NOT) from a sample of 31 candidates. Hence these three hot subdwarfs are new members of the EC 14026 class of pulsating sdB stars.
R. Østensen, J.-E. Solheim, U. Heber, R. Silvotti, S. Dreizler, H. Edelmann   +5 more
openaire   +1 more source

Orbital periods of 22 subdwarf B stars [PDF]

Monthly Notices of the Royal Astronomical Society, 2003
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 reside in binary systems today.
L. Morales-Rueda, P. F. L. Maxted, T. R. Marsh, R. C. North, U. Heber   +4 more
openaire   +3 more sources