Analyses of historical data suggest Sun is shrinking

At high noon on every clear day since 1750, astronomers at the Royal Greenwich Observatory have been measuring the diameter of the Sun. The quantity is a by‐product of a more fundamental measurement, which is to determine the precise position of the center of the Sun with respect to the stars. To do this, they record the time at which each limb of the Sun crosses the fixed meridian wire of an instrument. From the same data one can then calculate the horizontal solar diameter from the known rotation rate of the Earth.