Results 181 to 190 of about 3,404 (216)

Superflares on solar-type stars

Nature, 2012
Solar flares are caused by the sudden release of magnetic energy stored near sunspots. They release 10(29) to 10(32) ergs of energy on a timescale of hours. Similar flares have been observed on many stars, with larger 'superflares' seen on a variety of stars, some of which are rapidly rotating and some of which are of ordinary solar type.
Hiroyuki Maehara, Shota Notsu, Yuta Notsu   +2 more
exaly   +3 more sources

Oxygen Abundances in Solar-Type Stars

Astrophysics and Space Science, 1999
The absolute solar oxygen abundance, log e⨀ = 8.80 ± 0.06, has been determined from various oxygen abundance indicators in different solar atlases, and a new method is proposed to test collision rate coefficients for the NLTE model of O i. Using effective temperatures derived from Balmer lines, oxygen abundances from O i 7773 triplets in 83 solar-type ...
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Mass loss from solar-type stars

Solar Physics, 1985
Winds are directly detected from solar-type stars only when they are very young. At ages ~ 106 yr, these stars have mass loss rates ~ 106 times the mass flux of the present solar wind. Although these young T Tauri stars exhibit ultraviolet transition-region and X-ray coronal emission, the large particle densities of the massive winds lead to efficient ...
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Present Observational Status of Solar-type stars

Astrophysics and Space Science, 2003
Observing stellar oscillations provides a powerful probe for studying stellar interiors. The frequencies of these modes depend on the properties of the star and give strong constraints on stellar models and evolution theories. The five-minute oscillations in the Sun, induced by stochastic excitation of its convective zone, have provided a wealth of ...
François Bouchy, Fabien Carrier
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Rotational evolution of solar-type stars

Astrophysics and Space Science, 1981
The aim of the present investigation has been to consider rotational evolution of solar-type stars simulated by a polytropic model that possesses differential rotation of Clement's type. A properly defined reduction factor moderates the effects of such a rotation.
V. S. Geroyannis, G. A. Antonakopoulos
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The dynamo layer in solar‐type stars

Astronomische Nachrichten, 2005
AbstractThe role of the dynamo layer for dynamo action in solar‐type stars is discussed. As a result of instabilities, magnetic flux is expelled from the dynamo layer into the convection zone above it. The resulting partial evacuation of the dynamo layer and amplification of the deep‐seated toroidal magnetic field is investigated in an illustrative 3D ...
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How many single stars among solar-type stars?

2008
Finally, the question of the number of true single stars may be aborded. In our sample of nearby solar-type stars, we observe 44% of the primaries with at least one stellar companion. Corrected from detection biases and taking into account the very low mass secondaries down to 0.01 solar masses, this number rises to 71%.
A. Duquennoy, M. Mayor
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Effective temperatures of solar type stars

Astronomical & Astrophysical Transactions, 2002
For 29 stars of G0-G5 spectral types with color indices 0.60 \leq B\ndash V \le 0.68 and parallaxes obtained by Hipparcos satellite effective temperatures, angular diameters and radii are determined by means of the method of infrared fluxes (IRFM) on the basis of JHKLM photometry. Effective temperatures obtained by iterations in the process of combined
I. N. Glushneva, V. I. Shenavrin, I. A. Roshchina   +2 more
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