SOLAR CYCLE DEPENDENCE OF THE APPARENT RADIUS OF THE SUN.

These are his conclusions:

"According to Gough (2001), ground-based attempts to measure the solar radius have a long history with results of enormous disparity due to the distorting effects of the Earth's atmosphere.

Concerning periodic variations of the solar radius, there is a lack of consensus to accept its existence due to the marginal character of the reported evidence (Newkirk 1983). On the other hand, any measurable change of the solar radius would imply the action of processes that are not considered by the standard theories of the Sun (Ribes et al. 1991).

However, the results obtained during 13 years with the astrolabe of Santiago and most series of radius measurements of recent years, as well as the analysis of historical data that we have reviewed, show a clear convergence towards variations in time of the solar radius in phase with magnetic activity.

It is probable that the agreement shown in one of our figures by the radius measurements of Mount Wilson and Santiago based on quite different observing techniques, could be one of the strongest evidences presented so far that show a solar cycle dependence of the apparent radius."