Results 31 to 40 of about 44,379 (345)

Physical Properties of Radio Stars Based on LAMOST Spectral Survey

open access: yesUniverse, 2022
Radio emission has been detected for all types of stars in the Hertzsprung Russell diagram. Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low and medium-resolution spectroscopic surveys provide a good opportunity to obtain the ...
Liyun Zhang   +6 more
doaj   +1 more source

The formation mechanisms of classical emission line stars [PDF]

open access: yes, 2023
Classical emission line stars are known fast rotators hosting a decretion disc in which emission lines are formed. Since their discovery in 1866, the formation mechanism of this class of stars has proved difficult to identify.
Hastings, Ben James
core   +1 more source

THE MASSIVE STELLAR POPULATION IN THE DWARF STARBURST GALAXIES

open access: yesOdessa Astronomical Publications, 2017
The analysis of the long-slit spectral observations of 39 Wolf-Rayet (WR) galaxies with heavy element mass fraction ranging over 2 orders of magnitudes from Z☉/50 to 2Z☉ are presented.
N. G. Guseva
doaj   +1 more source

Photometric and spectroscopic study of five pre-main sequence stars in the vicinity of NGC 7129 [PDF]

open access: yesSerbian Astronomical Journal, 2019
We present results from long-term optical photometric and spectroscopic observations of five pre-main sequence stars, located in the vicinity of the bright nebula NGC 7129.
Semkov E.H., Ibryamov S.I., Peneva S.P.
doaj   +1 more source

Measurement of Interstellar Extinction in Emission Line Stars [PDF]

open access: yesSymposium - International Astronomical Union, 1970
Usually selective interstellar extinction is derived by comparing the spectrum of a reddened star with an unreddened nearby star, preferably of the same spectral type. But in many cases this comparison is not possible, so that new methods have to be used.A direct measure of this quantity is possible when a spectrum shows a number of emission lines as ...
openaire   +1 more source

Orbits and outflows of emission-line stars

open access: yes, 2022
The optical spectra of some stars exhibit spectral lines in emission, which is characteristic of them having powerful radiatively driven winds. These stars are known as emission-line stars.
Grant, David
core   +1 more source

Gamma Cas Stars as Be+White Dwarf Binary Systems

open access: yesThe 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   +2 more
doaj   +1 more source

EUV Emission Lines in the Atmospheres of Cool Stars [PDF]

open access: yesPhysica Scripta, 1987
High resolution far ultraviolet (1200-2000 A) spectra of 17 cool giant and supergiant stars have been obtained using the IUE satellite of ESA, NASA and UK. We have measured the line intensities, wavelengths and widths of approximately 200 EUV emission lines in these spectra, using a least squares gaussian fitting technique. Line identification has been
openaire   +1 more source

Gravitoastronomy with neutron stars [PDF]

open access: yes, 2004
Recent advances in gravitational wave detectors mean that we can start to make astrophysically important statements about the physics of neutron stars based on observed upper limits to their gravitational luminosity.
Woan, G., Graham Woan
core   +1 more source

The Orbital and Physical Properties of Five Southern Be+sdO Binary Systems

open access: yesThe Astronomical Journal, 2023
Close binary interactions may play a critical role in the formation of the rapidly rotating Be stars. Mass transfer can result in a mass gainer star spun up by the accretion of mass and angular momentum, while the mass donor is stripped of its envelope ...
Luqian Wang   +3 more
doaj   +1 more source

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