Results 31 to 40 of about 6,190,013 (295)

cx2204/stellar-radius: stellar radius microphysics

open access: yes, 2022
Full Changelog: https://github.com/cx2204/stellar-radius/commits/v1.
cx2204
core   +1 more source

Stellar population gradients in galaxy discs from the CALIFA survey : the influence of bars [PDF]

open access: yes, 2014
We acknowledge financial support from the research projects under grants AYA2010-21887-C04-03, AYA2010-21322-C03-03 and AYA2010-15081 by the Spanish Ministerio de Ciencia e Innovación.While studies of gas-phase metallicity gradients in disc galaxies are ...
Wisotzki, L.   +73 more
core   +1 more source

Stellar populations in active galaxies [PDF]

open access: yesProceedings of the International Astronomical Union, 2004
To appear in "The Interplay among Black Holes, Stars and ISM in Galactic Nuclei", T. Storchi Bergmann, L.C. Ho & H.R. Schmitt, eds., Proc IAU Symp 222 (Cambridge University Press)
openaire   +2 more sources

Stellar Activity Cycles

open access: yesSpace Science Reviews, 2023
AbstractThe magnetic field of the Sun is generated by internal dynamo process with a cyclic period of 11 years or a 22 year magnetic cycle. The signatures of the Sun’s magnetic cycle are observed in the different layers of its atmosphere and in its internal layers.
Jeffers, Sandra V.   +2 more
openaire   +2 more sources

Stellar chromospheric activity in main-sequence stars [PDF]

open access: yes
The research presented here presents a narrow slice of several largescale, ground-based astronomy surveys focused on chromospheric activity measurements of stars from the Keck Observatory.
Isaacson, Howard
core   +1 more source

Solar and Stellar Flares: Frequency, Active Regions, and Stellar Dynamo

open access: yesThe Astrophysical Journal, 2022
Abstract We demonstrate that for weak flares the dependence of their frequency occurrence on spottedness can be rather weak. The fact is that such flares can occur in both small and large active regions. At the same time, powerful large flares of classes M and X occur much more often in large active regions. In energy estimates, the mean
M. M. Katsova   +3 more
openaire   +2 more sources

Constraining planet structure from stellar chemistry : the cases of CoRoT-7, Kepler-10, and Kepler-93 [PDF]

open access: yes, 2015
This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. P.F., N.C.S., and S.G.S. also acknowledge support from FCT through Investigador FCT contracts of reference IF/01037/2013, IF/00169/2012,
Mortier, Annelies   +31 more
core   +3 more sources

Disentangling between stellar activity and planetary signals [PDF]

open access: yes, 2016
Photospheric stellar activity (i.e. dark spots or bright plages) might be an important source of noise and confusion in the radial-velocity (RV) measurements.
Hébrard, Guillaume   +11 more
core   +1 more source

Filamentary Electron-beam Heating in Solar Flares

open access: yesThe Astrophysical Journal
Radiation-hydrodynamic simulations of the solar-flare chromospheric emission very often lead to an excess of the line intensities when compared to observations.
Michalina Litwicka   +2 more
doaj   +1 more source

Asteroseismology and Spectropolarimetry of the Exoplanet Host Star λ Serpentis

open access: yesThe Astronomical Journal, 2023
The bright star λ Ser hosts a hot Neptune with a minimum mass of 13.6 M _⊕ and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun.
Travis S. Metcalfe   +33 more
doaj   +1 more source

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