Results 61 to 70 of about 199 (140)

Stars on the ascending helium giant branch

Astronomy & Astrophysics
Hot subdwarf stars with masses above 0.8 M⊙ ascend the helium giant branch after the end of core helium burning, before entering the white dwarf cooling track or exploding as type Ib/c supernovae.
Pritzkuleit M., Dorsch M., Miller Bertolami M. M., Geier S., Bradshaw C. W., Dawson H.   +5 more
doaj   +1 more source

Identifying hot subdwarf binaries with multimodal deep learning

Astronomy & Astrophysics
Context. Hot subdwarf stars are important tracers of stellar structure and evolution, while their binary systems provide key constraints on their formation channels. Nevertheless, the number of confirmed hot subdwarf binaries is still limited. Aims.
Li Qinqin, Bu Yude, Zhang Jiangchuan, Zhang Yuhang, Wang Ke, Yang Beining, Yi Zhenping, Kong Xiaoming, Liu Meng   +8 more
doaj   +1 more source

К ВОПРОСУ О ВКЛАДЕ ВЫРОЖДЕННЫХ КАРЛИКОВ БЛИЖАЙШИХ ОКРЕСТНОСТЕЙ СОЛНЦА, ГАЛО И НАСЕЛЕНИЯ III В МАССУ ТЕМНОЙ МАТЕРИИ

Odessa Astronomical Publications, 2011
The data about occurrence frequency of substars and white dwarfs among close stars are analyzed. The estimation of partial content of subdwarfs and stellar remains among populations II and III as function of power of initial mass function have been made.
В. А. Захожай, А. А. Минаков, В. М. Шульга   +2 more
doaj   +1 more source

SUBDWARFS: ABUNDANCE OF LIGHT ELEMENTS

Odessa Astronomical Publications, 2017
CNO abundances in the atmospheres of seven metal-deficient stars were derived by model atmosphere method on the basis of high dispersion Echelle spectra obtained using the 6-m telescope of the Special Observatory of the Russian Academy of Sciences. The O
T. V. Mishenina, V. G. Klochkova, V. E. Panchuk   +2 more
doaj   +1 more source

Microscopic diffusion and subdwarfs

, 1999
The recent distance determinations by HIPPARCOS have allowed to locate very precisely a reasonable set of subdwarfs in the HR diagram. A detailed comparison with evolutionary models is now possible and it has been recently claimed that the observed lower part of the main-sequence is cooler than the computed one.
Morel, P., Baglin, A.
openaire   +2 more sources

SuperWASP Lightcurves of Subdwarf Stars [PDF]

, 2008
SuperWASP is a wide angle survey for transiting hot-Jupiter exoplanets around bright ...
Maxted, P. F. L., Norton, A. J., West, R. G., Copperwheat, C., Marsh, T. R.   +4 more
openaire   +1 more source

PRELIMINARY ABUNDANCE ANALYSIS OF 9 SUBDWARFS

Odessa Astronomical Publications, 2017
We provide parameter and abundance determination of 9 subwarfs including two SMR stars (HD 161797 and HD 182572). These stars show metallicity overabundance in agreement with previous results.
T. V. Mishenina, T. I. Gorbaneva, L. E. Kantsen   +2 more
doaj   +1 more source

Hot subdwarf stars in close-up view [PDF]

Astronomy & Astrophysics, 2013
Context: Hot subdwarf B stars (sdBs) are considered to be core helium-burning stars with very thin hydrogen envelopes situated on or near the extreme horizontal branch (EHB). The formation of sdBs is still unclear as well as the chemical composition of their atmospheres. The observed helium depletion is attributed to atmospheric diffusion.
openaire   +2 more sources

Hot subluminous stars: Highlights from the MUCHFUSS and Kepler missions

EPJ Web of Conferences, 2013
Research into hot subdwarf stars is progressing rapidly. We present recent important discoveries. First we review the knowledge about magnetic fields in hot subdwarfs and highlight the first detection of a highly-magnetic, helium-rich sdO star.
Geier S., Heber U., Gaensicke B.
doaj   +1 more source

HR6819: a puffed-up stripped star system challenging stable mass transfer theory

Astronomy & Astrophysics
Context. HR6819 is the first system with a puffed-up low-mass stripped star + a classical Be star whose nature has been confirmed by optical interferometry.
Picco A., Marchant P., Sana H., Bodensteiner J., Shenar T., Frost A. J., Deshmukh K., Mombarg J. S. G., Pauli D., Willcox R., Kemp A.   +10 more
doaj   +1 more source