Results 21 to 30 of about 166,438,504 (289)

Using limb darkening to measure fundamental parameters of stars [PDF]

Astronomy and Astrophysics, 2012
Context. Limb darkening is an important tool for understanding stellar atmospheres, but most observations measuring limb darkening assume various parameterizations that yield no significant information about the structure of stellar atmospheres. Aims. We use a specific limb-darkening relation to study how the best-fit coefficients relate to fundamental
H R Neilson
exaly   +3 more sources

The Mass–Temperature Relation for B and Early A Stars Based on International Ultraviolet Explorer Spectra of Detached Eclipsing Binaries

The Astronomical Journal, 2023
Ultraviolet spectra were taken of 25 detached eclipsing binaries (DEBs) with spectral types O, B, and early A with the International Ultraviolet Explorer satellite in the 1150–1900 Å region. The spectra were compared with BOSZ model atmospheres.
Nancy Remage Evans, Mckenzie G. Ferrari, Joanna Kuraszkiewicz, Steven Silverberg, Joy Nichols, Guillermo Torres, Makenzi Fischbach   +6 more
doaj   +1 more source

Rotation: a fundamental parameter of massive stars [PDF]

Symposium - International Astronomical Union, 1997
Massive stars are rapid rotators. Equatorial rotation velocities span the range vrot = 100–400 km s−1, with B stars rotating closest to their break-up speed vcrit (Howarth et al. 1997). During the last decade, many observations have revealed unusual surface abundances that may require additional internal mixing (beyond that of simple convection and ...
Langer, Norbert (Prof. Dr.), Heer, A., Fliegner, Jana Ute   +2 more
openaire   +2 more sources

Fundamental Parameters of the W Serpentis Stars [PDF]

International Astronomical Union Colloquium, 1989
AbstractApplication of digital cross-correlation spectroscopy to the spectra of the W Serpentis binaries SX Cas and RX Cas has allowed an accurate determination of the orbits and rotations of the (mass-losing) K-subgiant secondary components. The distortion of the primary radial-velocity curves due to the influence of the prominent accretion disks in ...
J. Andersen, B. Nordström
openaire   +1 more source

The fundamental parameters of the roAp starγ Equulei [PDF]

Astronomy & Astrophysics, 2011
Physical processes working in the stellar interiors as well as the evolution of stars depend on some fundamental stellar properties, such as mass, radius, luminosity, and chemical abundances. A classical way to test stellar interior models is to compare the predicted and observed location of a star on theoretical evolutionary tracks in a H-R diagram ...
Perraut, K., Brandão, I., Mourard, D., Cunha, M., Bério, P., Bonneau, D., Chesneau, O., Clausse, J.M., Delaa, O., Marcotto, A., Roussel, A., Spang, A., Stee, P., Tallon-Bosc, I., Mcalister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., Goldfinger, P.J.   +20 more
openaire   +2 more sources

The fundamental parameters of the roAp star 10 Aquilae [PDF]

Astronomy & Astrophysics, 2013
Due to the strong magnetic field and related abnormal surface layers existing in rapidly oscillating Ap stars, systematic errors are likely to be present when determining their effective temperatures, which potentially compromises asteroseismic studies of these pulsators.
Perraut, K., Borgniet, S., Cunha, M., Bigot, L., Brandão, I., Mourard, D., Nardetto, N., Chesneau, O., Mcalister, H., ten Brummelaar, T., Sturmann, J., Sturmann, L., Turner, N., Farrington, C., Goldfinger, P.   +14 more
openaire   +2 more sources

The fundamental parameters of the roAp star α Circini [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
Abstract We have used the Sydney University Stellar Interferometer to measure the angular diameter of α Cir. This is the first detailed interferometric study of a rapidly oscillating A (roAp) star, α Cir being the brightest member of its class.
Bruntt, H., North, J. R., Cunha, M., Brandão, I. M., Elkin, V. G., Kurtz, D. W., Davis, J., Bedding, T. R., Jacob, A. P., Owens, S. M., Robertson, J. G., Tango, W. J., Gameiro, J. F., Ireland, M. J., Tuthill, P. G.   +14 more
openaire   +3 more sources

Modelling and observations of molecules in discs around young stars [PDF]

, 2013
This thesis contains a study of molecules within circumstellar discs around young stars. Firstly, the chemistry of a disc around a young, Class 0 protostar is modelled.
Ilee, John David
core   +6 more sources

Fundamental Parameters of Be Stars Seen Equator-On [PDF]

International Astronomical Union Colloquium, 2002
AbstractThe geometric deformation, as well as the non-uniform surface gravity and temperature distributions induced by the fast rotation, are taken into account to determine the fundamental parameters of 10 Be stars seen nearly equator-on. The stars occur in the first half of the main sequence evolutionary span, which suggests that their fast rotation ...
J. Zorec, Y. Frémat, A.M. Hubert, M. Floquet   +3 more
openaire   +1 more source

The fundamental parameters of the Ap star 78 Virginis [PDF]

Astronomy & Astrophysics, 2015
Context. Determining the effective temperature of Ap stars, including the roAp stellar pulsators, is a difficult task owing to their strong magnetic field and their related spotted surfaces. It is, however, an important step towards constraining models of their complex atmosphere and testing proposed pulsation excitation mechanisms. Aims.
K. Perraut, M. Cunha, I. Brandão, J. Loridat, D. Mourard, A. Meilland, N. Nardetto, H. McAlister, T. A. ten Brummelaar, J. Sturmann, L. Sturmann, N. Turner, C. Farrington, N. Vargas   +13 more
openaire   +3 more sources