Visibility of facular fields in Mgi b-lines |
| |
| Authors: | A A Galal |
| |
| Institution: | 1. Helwan Observatory, ARE, Cairo, Helwan, U.S.A.
|
| |
| Abstract: | On the basis of photoelectric observations, the center-to-limb variations of the brightness of restricted areas (≈0.5″ × 7.0″) of unresolved facular granules were determined at different frequencies in the lines λ5183 Å and λ5172 Å of Mgi. It was found that the chromospheric plages reach maximum intensity in the central parts of the lines at the same position on the solar disk where photospheric faculae have maximum brightness. The floccular emission is conspicuous in the cores of the lines up to a distance Δλ = 0.02 Å. In the portion of the lines corresponding to 0.02 Å < Δλ < 0.18 Å the contrast of flocculi decreases to a minimum value and then increases again in the inner wings of these lines. In the far wings the contrast of facular areas systematically decreases to the continuum values. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
