منابع مشابه
Ring Nebulae around Massive Stars throughout the HR Diagram
Massive stars evolve across the HR diagram, losing mass along the way and forming a variety of ring nebulae. During the main sequence stage, the fast stellar wind sweeps up the ambient interstellar medium to form an interstellar bubble. After a massive star evolves into a red giant or a luminous blue variable, it loses mass copiously to form a circumstellar nebula. As it evolves further into a ...
متن کاملUsing a Hipparcos Derived Hr Diagram to Limit the Metallicity Scatter of Stars in the Hyades – Are Stars Polluted?
Hipparcos parallaxes and proper motions have made it possible to construct Hertzsprung-Russell (HR) diagrams of nearby clusters with unprecedented accuracy. The standard deviation of high fidelity non-binary non-variable stars about a model stellar evolution isochrone in the Hyades cluster is about 0.04 magnitudes. We use this deviation to estimate an upper limit on the scatter in metallicities...
متن کاملSpectral classification and HR diagram for symbiotic stars in the galactic bulge
A sample of 45 symbiotic stars observed in the direction of the galactic bulge are classified in spectral type using TiO λ 6180, 7100 Å and VO λ 7865 Å absorption feature indices and visual comparison. The effective temperatures obtained are used together with K data from the literature to estimate the bolometric luminosity of the giant components if located at d=8.5 kpc. The (T eff , L/L ¤) pa...
متن کاملSubluminous B Stars and Progenitors of Helium Core White Dwarfs
It is now generally accepted that the subluminous B (sdB) stars can be identified with models for Extreme Horizontal Branch (EHB) stars burning He in their core, but with a very tiny inert hydrogen envelope (Heber, 1986). An EHB star bears great resemblance to a helium main-sequence star of half a solar mass and its further evolution should proceed similarly (i.e. directly to the white dwarf gr...
متن کاملDamping rates of solar-like oscillations across the HR diagram
The space-borne missions CoRoT and Kepler are providing a rich harvest of high-quality constraints on solar-like pulsators. Among the seismic parameters, mode damping rates remains poorly understood and are thus barely used to infer the physical properties of stars. Nevertheless, thanks to the CoRoT and Kepler spacecrafts it is now possible to measure damping rates for hundreds of main-sequence...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1978
ISSN: 0074-1809
DOI: 10.1017/s007418090014536x