Detection of Low-Lattitude Plumes in the Outer Corona by Ulysses Radio Ranging Measurements

Plumes have been detected beyond the field of view of coronagraphs in the range of 23-42 R(sub o) in an equatorial coronal hole by Ulysses radio ranging measurements conducted in 1991 at 13 and 3.6 cm wavelengths. These results show that plumes are not exclusive to polar regions, but appear to be intrinsic to open magnetic field regions at any latitude.