منابع مشابه
Differential Rotation in F Stars
Differential rotation can be detected in single line profiles of stars rotating more rapidly than about v sin i = 10 km s with the Fourier transform technique. This allows to search for differential rotation in large samples to look for correlations between differential rotation and other stellar parameters. I analyze the fraction of differentially rotating stars as a function of color, rotatio...
متن کاملDifferential rotation in rapidly rotating F - stars ⋆ , ⋆ ⋆
We obtained high quality spectra of 135 stars of spectral types F and later and derived " overall " broadening functions in selected wavelength regions utilizing a Least Squares Deconvolution (LSD) procedure. Precision values of the projected rotational velocity v sin i were derived from the first zero of the Fourier transformed profiles and the shapes of the profiles were analyzed for effects ...
متن کاملCa II activity and rotation in F-K evolved stars
Ca II H and K high resolution observations for 60 evolved stars in the field and in 5 open clusters are presented. From these spectra chromospheric fluxes are derived, and a homogeneous sample of more than 100 giants is built adding data from the literature. In addition, for most stars, rotational velocities were derived from CORAVEL observations. By comparing chromospheric emission in the clus...
متن کاملA–type stars: evolution, rotation and binarity
We discuss the internal structure of stars in the mass range 1.5 to 4M⊙ from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are considered such as overshooting, treatment of convection, microscopic diffusion and rotation. Their influence on the internal structure and on the photospheric chemical a...
متن کاملThe Age – Activity – Rotation Relationship in Solar – Type Stars . ⋆
Measured from high–resolution spectra, we present Ca II K line chromospheric fluxes in 35 G dwarf stars of 5 open clusters to determine the age–activity–rotation relationship from the young Hyades and Praesepe (0.6 Gyr) to the old M 67 (∼ 4.5 Gyr) through the two intermediate age clusters IC 4651 and NGC 3680 (∼ 1.7 Gyr). The full amplitude of the activity index within a cluster is slightly abo...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1953
ISSN: 0004-6256
DOI: 10.1086/106870