That part of the Milky Way galaxy lying near the Sun. In fact there is no definition of the exact radius of this region. It is referred to the immediate solar neighborhood (within about 5 pc), the sol
ar neighborhood (within about 25 pc), and the extended solar neighborhood (within a few hundred pc).
That part of the Milky Way galaxy lying near the Sun. In fact there is no definition of the exact radius of this region. It is referred to the immediate solar neighborhood (within about 5 pc), the sol
ar neighborhood (within about 25 pc), and the extended solar neighborhood (within a few hundred pc).
A major discrepancy between the flux of neutrinos detected at Earth from the solar core and that predicted by current models of solar nuclear fusion and our understanding of neutrinos themselves. The
problem, lasting from the mid-1960s to about 2002, was a considerably lesser detected number of neutrons compared with theoretical predictions. The discrepancy has since been resolved by new understanding of neutrino physics, requiring a modification of the standard model of particle physics, in particular neutrino oscillation.
A major discrepancy between the flux of neutrinos detected at Earth from the solar core and that predicted by current models of solar nuclear fusion and our understanding of neutrinos themselves. The
problem, lasting from the mid-1960s to about 2002, was a considerably lesser detected number of neutrons compared with theoretical predictions. The discrepancy has since been resolved by new understanding of neutrino physics, requiring a modification of the standard model of particle physics, in particular neutrino oscillation.
A neutrino generated in the Sun. The main source of solar neutrinos is the proton-proton chain of reactions, in which an energy of +28 MeV is shared between the reaction products. These are called low
-energy neutrinos. There are less important reactions in the Sun yielding a smaller flux of higher energy neutrinos. The solar neutrino flux can be estimated from the solar luminosity.
A neutrino generated in the Sun. The main source of solar neutrinos is the proton-proton chain of reactions, in which an energy of +28 MeV is shared between the reaction products. These are called low
-energy neutrinos. There are less important reactions in the Sun yielding a smaller flux of higher energy neutrinos. The solar neutrino flux can be estimated from the solar luminosity.
The visible surface of the Sun (temperature 5700 K), just below the chromosphere and just above the convective zone. The solar photosphere is a thin layer of roughly 300 km wide. Its temperature decre
ases uniformly with height, from about 6,600 K (pressure 0.868 millibars) at its bottom, to about 4,400 K (pressure 125 mb), where it merges with the chromosphere. The photosphere has a 'rice-grain' appearance, called granulation, caused by rising (hot) and falling (cool) material in the convective cells just below the photosphere. Other main features of the photosphere are sunspots, faculae, and supergranulation.
The branch of astrophysics concerned with the study of the physical properties of the Sun based on the most detailed observations which can be obtained for a star.