Results 101 to 110 of about 513 (133)
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A search for continuous ultraviolet opacity sources in the Sun's photosphere
Solar Physics, 1973Experimental results on limb darkening and specific intensities imply more ultraviolet continuous opacity than that predicted by theoretical calculations. Some atomic and molecular processes, not yet studied from this standpoint are investigated as to their importance on the continuous absorption coefficient.
LANDI DEGL'INNOCENTI, EGIDIO +1 more
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Diagnostics of the Quiet Sun Atmosphere’s Photospheric Jets
Kinematics and Physics of Celestial Bodies, 2019Abstract—From 2D-spectral observation data of a quiet region of the solar disk center in the Fe I λ 557.609 nm line, 3D hydrodynamic models of photospheric jets are built by solving the inverse radiative transfer problem. The obtained models describe thermodynamic parameters and the complete velocity field (vertical and horizontal).
M. I. Stodilka +2 more
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Surges of the weak magnetic field in the photosphere of the Sun
2021<p>The properties of the magnetic fields of the solar photosphere are investigated, in particular, the distribution of fields of different polarity over the solar surface. As primary data, synoptic maps of the photospheric magnetic field of the Kitt Peak National Solar Observatory for 1978-2016 were used. Using the vector summation method,
Dmitrii Baranov +2 more
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Some Photospheric Characteristics of the Sun as a Star
1982Many non- classical solar features are common among stars. Those features influence spectral lines, and for stellar spectra diagnostic one must know how to discern that influence from other peculiarities of stellar spectra. But one can learn a lot about stellar atmospheres by extending what one knows about the Sun.
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A comparison of photospheric, chromospheric and coronal indices for the sun
Advances in Space Research, 1986Abstract Indices of photospheric activity as reconstructed sunspot blocking (essentially sunspot areas) are compared with the White and Livingston 1A Ca II K index and a polarization-brightness index of the corona that is proportional to mean hemispheric coronal electron density.
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The Large-Scale Structures Of The Quiet-Sun Photosphere
Solar Physics, 2001The area density distribution of bright photospheric points on the quiet solar surface is not uniform. The distributions show some considerable pecularities. This article is a study of their characteristics during the four last solar activity minima in Bartels longitudes.
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The Spontaneous Concentration of Magnetic Field in the Photosphere of the Sun
1981Magnetic fields at the surface of the sun exhibit the remarkable property of fragmentation and concentration into separate tubes of 1–2 kilogauss. In newly emerging active regions the separate tubes cluster together to produce the sunspot phenomenon, with the magnetic field compressed further, to 2–4 kilogauss.
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Quantifying the sun’s magnetic stress with the photospheric flows
Bulletin of the AAS, 2023Raphael Attie +5 more
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Cooling of the Sun's photosphere coincident with increased sunspot activity
Nature, 1978IN summer 1975, I began to monitor the spectroscopic temperature of integrated sunlight (‘the Sun viewed as a star’). The first 1.5 yr of observations were taken at a time of minimum activity and the full disk temperature was apparently constant at ±1–2 K. However, 1977 produced a marked increase of activity with the onset of cycle no. 21.
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Would the Sun's photosphere be negatively charged and magnetized ?
2019"No satisfactory solution has been found as yet for the unexpectedly small vertical gradients [with respect to the observed ones] obtained by applying the divB=0 condition [to the solar photosphere magnetic field measurements]" (S. Solanki, 2003, Astron. Astrophys. Rev. 11, p. 184).
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