S&T readers joined expeditions to determine the precise edges of solar eclipses back when this was the state of the art for measuring the
solar diameter. Changes that were reported were extremely tiny and depended confusingly on the technique used, the wavelength of light observed, and exactly how the Sun's "edge" was defined.
These solar eclipse observations in turn are used to measure small but climatically significant variations in the
solar diameter, but their use for this purpose is limited by our current knowledge of lunar topography."
At three locations near Agra, teams for the International Occultation Timing Association measured the
solar diameter to detect possible variations.
That's about two
solar diameters. Binoculars will help.
The model predicted the existence of almost 10 times more objects on orbits that approach the Sun to within 10
solar diameters than the researchers actually observed.