Coronal temperatures, heating, and energy flow in a polar region of the sun at solar maximum

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163531· OSTI ID:5612615

Withbroe, G L; Kohl, J L; Weiser, H; Munro, R H

The profiles of resonantly scattered Lyman-alpha coronal radiation have been used to determine the hydrogen kinetic temperature from 1.5 to 4 solar radius from the center of the polar region of the corona observed in 1980 at solar maximum. Hydrogen temperatures derived from the line profiles were found to decrease with height from 1.2 million K at r = 1.5 solar radii to 600,000 K at r = 4 solar radius. Comparison of the measured kinetic temperatures with predictions from a semiempirical two-fluid model showed evidence of a small amount of heating or a nonthermal contribution to the motions of coronal protons between 1.5 and 4 solar radius. The widths of the profiles confirmed an upper limit of 110 + or - 15 km/s on the rms magnitude of the line-of-sight component of velocities between 1.5 and 4 solar radius. Density measurements obtained in situ in the solar wind in the ecliptic were used to locate the sources of low speed and high-speed winds in the polar region. An eclipse photograph of the corona at solar maximum is provided. 31 references.

• Research Organization: Harvard-Smithsonian Center for Astrophysics, Cambridge, MA; High Altitude Observatory, Boulder, CO
• OSTI ID: 5612615
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 297; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
ENERGY SPECTRA
HEATING
HYDROMAGNETIC WAVES
LYMAN LINES
PLASMA HEATING
RADIATIONS
SOLAR ACTIVITY
SOLAR CORONA
SOLAR RADIATION
SOLAR WIND
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION
TEMPERATURE MEASUREMENT