Solar-cycle dependence of the Sun's apparent radius in the neutral iron spectral line at 525 nm
Article Abstract:
The Sun's apparent radius is dependent on the solar-cycle when viewed in the 525 nm neutral iron spectral line. Though sunspots reduce the radius, this effect is counteracted by magnetic activities such as photospheric faculae. Total irradiance is composed of between .013% and .025% apparent radii variation with total variation being .1%. The proximity of frequencies to both the solar maximum and the atmospheric cutoff indicate that the solar atmosphere's temperature profile changes are the most likely cause of the frequency increases while the variances fluctuate in phase with solar magnetic activity.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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Long-term solar brightness changes estimated from a survey of Sun-like stars
Article Abstract:
Reliable data on the 11-year solar cycle has been available for only two or three cycles, yet research based on correlations of sunspot and solar constant variations since 1978 has extrapolated the relation into the past. On this basis it is alleged that larger brightness variations occurred between AD 1645 and 1715. However, data compiled from eight years of observation of 33 stars resembling the Sun show that it may be in an unusually stable period and cast doubt on long-term inferences.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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High-frequency acoustic waves are not sufficient to heat the solar chromosphere
Article Abstract:
The detection of high-frequency waves, and other factors is reported and numerical simulations are used to show that acoustic energy flux of these waves is too low, by a factor of atleast ten, to balance the radiative losses in the, solar chromosphere. Acoustic waves therefore cannot constitute the dominant heating mechanism of the solar chromosphere.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2005
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