Faculae, filigree and calcium bright points

Abstract

Simultaneous observations of fine structure photospheric features at several wavelengths are described. The observations, which include regions near disk center and at the limb, were obtained using a narrow band calcium filter and selected wavelengths in Mg b₁, the red wing of Hα and the Hα continuum using the Universal Birefringent Filter of the Sacramento Peak Observatory.

From the disk-center series it is concluded that bright point structures seen in calcium are cospatial with the Hα filigree and are related in origin.

The limb photographs confirm that the calcium network is cospatial with the white light faculae. However, in regions of good seeing it is clear that even at the limb the calcium network patterns consist of individual bright points which are essentially the same as those seen near disk center.

Thus it is concluded that the white light faculae, the Hα filigree and the calcium bright points are different manifestations of the same photospheric features.