Photospheric and chromospheric magnetic activity of seismic solar analogs [PDF]
Astronomy and Astrophysics, 2016 Accepted for publication in A& ...
D. Salabert +9 more
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The Structure of the Lower Solar Chromosphere in Undisturbed and Active Regions [PDF]
Symposium - International Astronomical Union, 1968 As observational material in this work we used spectroheliograms taken with the Crimean solar tower telescope in K232 and Hα filtergrams taken with the chromospheric telescope in Simeis. The Hα birefringent filter was so adjusted, that by tuning the last polaroid we could take filtergrams in the centre of Hα or combined filtergrams in the two wings at ...
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Chromospheric activity and ages of solar-type stars
The Astrophysical Journal, 1987 Observations of 15 solar-type stars in the intermediate-age open cluster NGC 752 are reported. A lower resolution analog of the Mount Wilson S index is shown to yield absolute chromospheric surface flux values for these stars with about 60 percent of the sensitivity of the Mount Wilson system.
Don C. Barry +2 more
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Photospheric high-frequency acoustic power excess in sunspot umbra: signature of magneto-acoustic modes [PDF]
, 2013 We present observational evidence for the presence of MHD (magnetohydrodynamic) waves in the solar photosphere deduced from SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) Dopplergram velocity observations.
Shelyag, S. +14 more
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Chromospheric Magnetic Field of Solar Active Regions
The Astrophysical Journal, 2001 The three-dimensional magnetic field structure of 137 solar active regions is studied by comparing the observed and computed chromospheric magnetograms. The model chromospheric field is obtained by extrapolating the observed photospheric field into the chromosphere with a potential (current-free) magnetic-field model in Cartesian geometry.
Debi Prasad Choudhary +2 more
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Chromospheric activity and evolutionary age of the Sun and four solar twins [PDF]
Astronomy & Astrophysics, 2016 8 pages, 7 figures, accepted for publication in A& ...
Mittag, M. +4 more
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IRIS observations of chromospheric heating by acoustic waves in solar quiet and active regions [PDF]
Astronomy & Astrophysics, 2021 Aims. To study the heating of solar chromospheric magnetic and nonmagnetic regions by acoustic and magnetoacoustic waves, the deposited acoustic-energy flux derived from observations of strong chromospheric lines is compared with the total integrated radiative losses. Methods.
V. Abbasvand +5 more
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CHROMOSPHERICALLY ACTIVE STARS IN THE RAVE SURVEY. II. YOUNG DWARFS IN THE SOLAR NEIGHBORHOOD [PDF]
The Astrophysical Journal, 2017 ABSTRACT A large sample of over 38,000 chromospherically active candidate solar-like stars and cooler dwarfs from the RAVE survey is addressed in this paper. An improved activity identification with respect to the previous study was introduced to build a catalog of field stars in the solar neighborhood with an excess emission flux in the
Žerjal, M +21 more
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Co-existence of two plasma phases in solar and AGN coronas [PDF]
Serbian Astronomical Journal, 1998 Here we have juxtaposed two distant cosmic locations of the Sun and AGN where neutral hydrogen appears in a close connection with hot coronas. Besides the solar photosphere, chromosphere and prominences where the presence of neutral hydrogen is ...
Kubičela A. +4 more
doaj +1 more source
Fine structure of the chromospheric activity in Solar-type stars – The Hα line [PDF]
Astronomy & Astrophysics, 2005 10 pages, 10 figures, accepted for publication in Astronomy & Astrophysics. Nature of replacement: match astro-ph and ADS title (greek letter)
Lyra, W., de Mello, G. F. Porto
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