The mean coronal magnetic field determined from Helios Faraday rotation measurements

摘要: Coronal Faraday rotation of the linearly polarized carrier signals HELIOS spacecraft was recorded during regularly occurring solar occultations over almost a complete cycle from 1975 to 1984. These measurements are used determine average strength and radial variation coronal magnetic field at minimum distances 3–10 radii, i.e., range which complex fields base transformed into interplanetary spiral. The mean in 1975–1976 found decrease with distance according r −α, where α = 2.7 ± 0.2. magnitude 1.0 0.5 × 10 −5 tesla nominal 5 radii. Possibly higher strengths were indicated maximum, but lack data prevented statistical determination this epoch.