Results 21 to 30 of about 2,704,038 (287)

Studying the UV Mg II Resonance Lines in 20 Be Stars

Open Astronomy, 2011
Using the GR model, we analyze the UV Mg II resonance lines in the spectra of 20 Be stars of different spectral subtypes, in order to detect the presence of satellite or discrete absorption components. The values of some physical parameters – rotational,
Antoniou A., Stathopoulos D., Danezis E., Lyratzi E.   +3 more
doaj   +1 more source

Stark Broadening of Carbon and Oxygen Lines in Hot DQ White Dwarf Stars: Recent Results and Applications

Open Astronomy, 2011
White dwarf stars are traditionally found to have surface compositions made primarily of hydrogen or helium. However, a new family has recently been uncovered, the so-called hot DQ white dwarfs, which have surface compositions dominated by carbon and ...
Dufour P., Nessib N. Ben, Sahal-Bréchot S., Dimitrijević M. S.   +3 more
doaj   +1 more source

Accurate fundamental parameters for 23 bright solar-type stars [PDF]

, 2010
We combine results from interferometry, asteroseismology and spectroscopy to determine accurate fundamental parameters of 23 bright solar-type stars, from spectral type F5 to K2 and luminosity classes III to V. For some stars we can use direct techniques
Aerts, Alekseeva, Allende Prieto, Ammler-von Eiff, Arentoft, Asplund, Aufdenberg, B. Smalley, Basu, Bedding, Bedding, Bessell, Bigot, Bouchy, Bouchy, Breger, Bruntt, Bruntt, Bruntt, Bruntt, Caffau, Carrier, Carrier, Chaplin, Christensen-Dalsgaard, Christensen-Dalsgaard, Cox, Di Folco, Dravins, Dravins, Dravins, Edvardsson, Eggenberger, Engels, F. Carrier, Flower, Frandsen, Fuhrmann, Fuhrmann, Fuhrmann, Fuhrmann, G. Lo Curto, Gatewood, Ghezzi, Girard, Girardi, Gray, Grevesse, Grundahl, Guenther, Gustafsson, H. Bruntt, Hayes, Hinkle, Holmberg, Holmberg, Kervella, Kervella, Kiehling, Kjeldsen, Kjeldsen, Kjeldsen, Kupka, Kurucz, Landstreet, M. Bazot, Mayor, Morel, Mosser, Mozurkewich, Mozurkewich, Neuforge-Verheecke, Nordgren, Nordgren, North, North, Olsen, P.-O. Quirion, Perryman, Petrov, Pijpers, Porto de Mello, Pourbaix, R. P. Butler, Reddy, Reiners, Saar, Santos, Santos, Smith, Soubiran, Sousa, Stello, Stello, Söderhjelm, T. Arentoft, T. H. Dall, T. R. Bedding, Teixeira, Thomas, Thompson, Thévenin, Ulrich, Valenti, Van Belle, Van Belle, Van Leeuwen, VandenBerg, Vauclair   +108 more
core   +4 more sources

Solar astrophysical fundamental parameters [PDF]

SPIE Proceedings, 2014
The accurate determination of the solar photospheric radius has been an important problem in astronomy for many centuries. From the measurements made by the PICARD spacecraft during the transit of Venus in 2012, we obtained a solar radius of 696,156±145 kilometres. This value is consistent with recent measurements carried out atmosphere.
Meftah, Mustapha, Irbah, Abdanour, Hauchecorne, Alain   +2 more
openaire   +2 more sources

On the fundamental nature of the state parameter [PDF]

Géotechnique, 2022
The state parameter ψ is widely used for soil characterisation and as a controlling parameter in modern constitutive understanding of soil, but there remains a perception that the control of soil strength by ψ is merely that of a correlation. This perception possibly stems from ψ having been introduced from ‘principles’ of critical state theory rather
openaire   +1 more source

Photometry and Classification of Stars in the Direction of the Dark Cloud TGU 619 in Cepheus. II. Interstellar Extinction and Cloud Distance

Open Astronomy, 2011
Interstellar extinction is investigated in a 1.5 square degree area of the Cepheus Flare in the direction of the dark cloud TGU 619 at ℓ=102.5°, b=+15.5°.
Zdanavičius K., Maskoliūnas M., Zdanavičius J., Straižys V., Kazlauskas A.   +4 more
doaj   +1 more source

Setting Up of the Strömvil System Standards and Standard Regions

Open Astronomy, 2003
CCD photometry of standard areas of the seven-color Strömvil photometric system in some open and globular clusters is described. The primary standards are being measured with a two-channel photoelectric photometer on the 1.5 meter telescope on Mt. Lemmon.
Philip A. G. Davis, Boyle R. P., Straižys V., Kazlauskas A.   +3 more
doaj   +1 more source

Fundamental Parameters of four Massive Eclipsing Binaries in Westerlund 1 [PDF]

, 2011
We present fundamental parameters of 4 massive eclipsing binaries in the young massive cluster Westerlund 1. The goal is to measure accurate masses and radii of their component stars, which provide much needed constraints for evolutionary models of ...
A. Z. Bonanos, Andersen, Belczynski, Bonanos, Bonanos, Bonanos, Bonanos, Clark, Clark, Clark, Crowther, Dressler, E. Koumpia, Ekström, Gennaro, Gräfener, Hamann, Hamann, Hillier, Indebetouw, Kelson, Kelson, Kothes, Lanz, Lanz, Martins, Massey, Muno, Negueruela, Negueruela, North, Perrier, Prša, Rauw, Ritchie, Roman-Lopes, Schaerer, Schaerer, Schaller, Schmutz, Stroud, Torres, Wilson   +42 more
core   +3 more sources

Fundamental parameters from precision tests [PDF]

Journal of Physics G: Nuclear and Particle Physics, 2002
9 pages, 4 figures, Talk presented at the Symposium in Honor of Alberto Sirlin, NYU, NY, October ...
openaire   +2 more sources

Some Photometric Characteristics of Population II Orbital Visual Binary Stars

Open Astronomy, 2003
A MV ,B−V diagram for metal-deficient, kinematically selected thick disk and halo visual binary stars with known orbits is presented. The magnitude differences Δm between the components are analyzed.
Bartkevičius A., Gudas A.
doaj   +1 more source