Apparent solar diameter and variability

Abstract

Philippe Delache brought me to solar physics in late June 1992. The first things he began with was the diameter of the Sun as it is measured at the “plateau de Calern”, and my first work was to analyze this time series in order to separate the “noise” from the pertinent information (section 2). Wet then applied the technique developed for this purpose to the study of the 11-year solar cycle as seen in the Wolf sunspot number (section 3) and I continued in collaboration with Judit Pap with the study of total irradiance and some other solar indicators which could help to understand its variations (section 4).