Holes in the Sun

Abstract

When Mariner 2 kept watch over the Sun from 1962 to 1974, holes developed occasionally in the Sun's corona for just a matter of months. But new data from Ulysses and confirmed by ground and satellite instruments suggests that the solar‐wind producing holes can persist for years.While making its solar polar pass, Ulysses detected a recurring 26‐day pattern in the flux of energetic particles, a pattern which lasted two years. The spacecraft also detected a corresponding variation in solar wind speed that lasted for a full year.