WebbWolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon.The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds.The surface temperatures of … Webbthe stellar metallicity (Maldonado et al.2015a). Stellar masses and luminosities for M dwarfs were obtained from the derived temperatures and metallicities by using empirical calibrations. The total number of stars in our sample amounts to 551. It is composed of 71 F-type stars, 261 G-type stars, 166 K-type stars,
Stellar Populations of Galaxies- - UMD
Webb26 aug. 2015 · The super-solar metallicity stars were likely formed closer to the galactic center or from the disk. The authors point out that current models of the star formation … Webbpopulation properties and the normalisation of the stellar initial mass function (IMF) measured using stellar dynamics, based on a large sample of 260 early-type galaxies observed as part of the ATLAS 3D project. This measure of the IMF normalisation is found to vary non-uniformly with age- and metallicity-sensitive absorption line strengths. clinically diagnosed diseases
Connecting substellar and stellar formation: the role of the host star …
Webb13 apr. 2024 · Related: Our sun is a weirdly 'quiet' star — and that's lucky for all of us "In the community, there is an ongoing debate on whether the sun is a 'sun-like' star," Santos said in a statement ... WebbStellar classes typically have three elements: a letter (O-B-A-F-G-K-M), an Arabic number between 0 and 9, and a Roman number between I and VII ... (AGB) stars. They can become blue giants depending on mass and metallicity. White giants. Some class A stars may be called white giants. Thuban in the constellation Draco is an example of this. An A-type main-sequence star (AV) or A dwarf star is a main-sequence (hydrogen burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1.4 and 2.1 solar masses (M☉) and have surface temperatures between 7,600 and 10,000 K. Bright and nearby examples are Altair (A7), Sirius A (A1), and clinically driven definition