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 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...
متن کاملButterfly Diagram and Activity Cycles in Hr 1099
We analyze photometric data of the active RS CVn–type star HR 1099 for the years 1975–2006 with an inversion technique and reveal the nature of two activity cycles of 15–16 yr and yr duration. The 16 yr cycle is 5.3 0.1 related to variations of the total spot area and is coupled with the differential rotation, while the 5.3 yr cycle is caused by the symmetric redistribution of the spotted area ...
متن کاملOscillation Power as a Test of Stellar Turbulence : Scanning the Hr Diagram
The acoustic power injected by turbulent convection into solar-like oscillations depends on the details of the turbulent spectrum. A theoretical formulation for the oscillation power is developed which generalizes previous ones. The formulation is first calibrated on a solar model in such a way as to reproduce the solar seismic data. This allows to investigate different assumptions about the st...
متن کاملAge and Morphology of the Main Sequence from Hipparcos Hr Diagram Data
With the help of new recent stellar models, we have studied the distribution in the HR diagram of 2170 stars from the Hipparcos database, subdivided into diierent groups according to their total velocities with respect to the local Keplerian reference frame and into diierent groups of metallicity. We discuss the morphology of the main sequence at the boundary between radiative and convective st...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1978
ISSN: 0074-1809
DOI: 10.1017/s0074180900145322