Chromospheric Fine Structures near the Solar Limb in Hα

Abstract

The solar limb has been studied visually and photographically in the light of Ha and the combined results are reported. The appearance of a spicule changes with wavelength settings. Effects due to changes of spicule velocities with height and opacity-wavelength relations are indicated. A number of bright spicules seen in the wings are identified with bright mottles seen in the line core. The dark band appears between Δλ= ±1.0 Å and Δλ= ± 0.70 Å. Examination of a small mottle cluster in a series of photographs taken in steps from Hα+0.85 Å to Hα+0.10 Å leads to a three-dimensional model of a typical mottle cluster.