Results 21 to 30 of about 6,299 (262)
THE SOLAR FLARE IRON ABUNDANCE [PDF]
The Astrophysical Journal, 2012 The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in {\em RHESSI} X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work.
Phillips, K. J. H., Dennis, B. R.
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The Astrophysical Journal, 2023 We present the first isotopic abundances of both ^13 CO and C ^18 O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions.
David R. Coria +5 more
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Frontiers in Astronomy and Space Sciences, 2019 Since the first observations of solar oscillations in 1960, helioseismology has probably been one of the most successful fields of astrophysics.
Gaël Buldgen +4 more
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The Astrophysical Journal, 2023 The relationship between coronal mass ejections (CMEs) and flares is an important issue in solar and stellar physics. The studies on the origination and generation mechanisms of interplanetary CME (ICME) materials are crucial for understanding the ...
Hui Fu +4 more
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Odessa Astronomical Publications, 2017 Detailed analysis of chemical abundances determined from high-resolution CCD-spectrogram of supergiant star PMMR23 (K5 I) in SMC is presented. The observation were obtained at 3.6 meter ESO La Silla telescope by Hill (1997).
S. V. Vasil'eva +3 more
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Is there a solar signal in lower stratospheric water vapour? [PDF]
Atmospheric Chemistry and Physics, 2015 A merged time series of stratospheric water vapour built from the Halogen Occultation Instrument (HALOE) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) data between 60° S and 60° N and 15 to 30 km and covering the years 1992 to
T. Schieferdecker +3 more
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Solar Elemental Abundances [PDF]
, 2020 Solar elemental abundances, or solar system elemental abundances, refer to the complement of chemical elements in the entire Solar System. The Sun contains more than 99% of the mass in the solar system and therefore the composition of the Sun is a good proxy for the composition of the overall solar system.
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Varying Calcium Abundances in Solar Flares Seen by the Solar Maximum Mission
The Astrophysical Journal, 2023 We report on calcium abundance A (Ca) estimates during the decay phases of 194 solar X-ray flares using archived data from the Bent Crystal Spectrometer (BCS) on the Solar Maximum Mission (operational 1980–1989). The abundances are derived from the ratio
B. Sylwester +3 more
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Solar Wind Helium Abundance Heralds Solar Cycle Onset [PDF]
Solar Physics, 2021 Abstract We study the solar wind helium-to-hydrogen abundance's ( A He ) relationship to solar cycle onset. Using OMNI/Lo data, we show that A He increases prior to sunspot number (SSN) minima. We also identify a rapid depletion and recovery in A He that occurs directly prior to cycle onset.
Benjamin L. Alterman +3 more
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Distribution of Heavy-Element Abundances Generated by Decay from a Quasi-Equilibrium State
UniverseWe present a freeze-out approach for describing the formation of heavy elements in expanding nuclear matter. Applying concepts used in modeling heavy-ion collisions or ternary fission, we determine the abundances of heavy elements taking into account in ...
Gerd Röpke +2 more
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