On the Determination of the Quiet-Sun Center-to-Limb Variation in Ca II K Spectroheliograms

Author: Brandt P.N.   Steinegger M.  

Publisher: Springer Publishing Company

ISSN: 0038-0938

Source: Solar Physics, Vol.177, Iss.1, 1998-01, pp. : 287-294

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

We present a method for the determination of the center-to-limb variation (CLV) for Caii K spectroheliograms. It is based on the calculation of intensity histograms for rings of constant area. Using a simple cutoff criterion in the cumulative histograms, we are able to derive CLVs of the quiet Sun regardless of the solar activity level. Using an example from the literature, we show in which way different methods of normalization of the quiet-Sun CLV may affect the results.