221 datasets found

The first stars in the history of the Universe are likely to form in the dense central regions of {sim.to}10^5^-10^6^ M_{sun} cold dark matter halos at z{approx}10--50. The...

Semiempirical atmospheric models of solar surface features as observed at moderate resolution are useful tools for understanding the observed solar spectral irradiance...

Chemical analyses of late-type stars are usually carried out following the classical recipe: LTE line formation and homogeneous, plane-parallel, flux-constant, and LTE model...

X-ray burst sources represent a class of accreting neutron stars in close binary systems which do not exhibit any traces of the magnetic field. We present new method of hot...

Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that...

Precise fundamental atmospheric stellar parameters and abundance determination of individual elements in stars are important for all stellar population studies. Non-local...

The ultraviolet-visible wavelength range holds critical spectral diagnostics for the chemistry and physics at work in planetary atmospheres. To date, time-series studies of...

We describe an application of the SEGUE Stellar Parameter Pipeline (SSPP) to medium-resolution stellar spectra obtained by the Large Sky Area Multi-Object Fiber Spectroscopic...

We have conducted spectrum analyses of 24 field metal-poor ([Fe/H]<-2) red horizontal-branch (RHB) stars identified in the HK objective-prism survey and 6 such stars in the...

We present a new calibration of optical (UBV, Stroemgren uvby{beta}, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars...

We present new grids of colors and bolometric corrections for F-K stars having 4000 K {<=} Teff {<=} 6500 K, 0.0 {<=} log(g) {<=} 4.5, and -3.0 {<=} [Fe/H]...

As part of a project to model the integrated spectra and colors of elliptical galaxies through evolutionary synthesis, we have refined our synthetic spectrum calculations of M...

We discuss a spectroscopic and photometric technique that enables the identification and classification of field horizontal-branch (FHB) and other A-type stars, even from...

More than 800 southern stars within 50pc have been observed for chromospheric emission in the cores of the Ca II H and K lines. Most of the sample targets were selected to be G...

We present monochromatic, passband-specific, and bolometric limb-darkening coefficients for a linear as well as nonlinear logarithmic and square root limb-darkening laws. These...

X-ray burst sources represent a class of accreting neutron stars in close binary systems which do not exhibit any traces of the magnetic field. We present the first detailed...

We have searched the literature for all observations of the ^12^CO(1-0), ^12^CO(2-1), and HCN(1-0) lines in circumstellar envelopes of late type stars published between January...

We present a library of synthetic spectra characterized by -2.5<=[Z/Z_{sun}]<=+0.5, 4.5<=logg<=1.0, and T_eff<=7500K computed at the same...

CCD spectra of the infrared triplet lines of ionized calcium at {lambda}{lambda}8498, 8542, 8662 have been obtained at a spectral resolution of 0.4{AA} in 146 stars brighter...

We have used recent Kurucz models and many standard stars to revise previous calibrations of the Geneva photometric parameters in terms of Teff, logg, and [M/H]. In addition,...