Rotation of Solar Corona from Tracking of Coronal Bright Points

Abstract

An automated procedure for identification of coronal bright points is applied to selected EIT images observed at various phases of the solar cycle. The procedure finds about 400 bright points on a single EIT image observed at 195 Å. The positions of the bright points are tracked to study the profile of solar rotation in the solar corona. It is shown that the rotation of coronal bright points closely follows the latitudinal rotation profile of the underlying photospheric magnetic field. It is also demonstrated that coronal features situated at the same heliographic coordinates but different heights in the corona may exhibit different rotation rates. © 2006. The American Astronomical Society. All rights reserved.