Evershed velocities in bipolar sunspots

Abstract

Spectra taken at the solar telescope-spectrograph, Kodaikanal, are analysed to find the sight-line velocity values in the regions between the opposite polarity sunspots. Velocities in opposite directions in the range 1 - 2.5 km per second are obtained in the cases of δ - type sunspots (spots having common penumbra), whereas opposite polarity sunspots having separate structures do not show any appreciable velocity in the regions between them. The velocities in the sunspots are restricted to the penumbral boundaries.