Motions in the Chromosphere Near Sunspots

Abstract

The Evershed velocities in the chromosphere have been studied from Hex filtergrams. Inward motions are found in the region extending from the outer boundary of the penumbra out to two sunspot radii; the moving matter is not evenly distributed around the spot but flows in along channels. These have lifetimes of about 9 hr, very long as· compared with the time of passage at inflow velocities of 45 km/sec. The velocity vector makes an angle of about 13° with the solar surface, suggesting that the matter is constrained to flow along lines of magnetic force. If so, the high velocities of inflow appear to be purely gravitational.