Secular Acceleration of Io Derived from Mutual Satellite Events

Abstract

Timings and light curves of the mutual phenomena of the Galilean satellites in 1908, 1914, and 1973–1997 have been used first to improve the values of the most important parameters in Sampson's satellite theory (published in 1921) and second to reduce the considerable remaining discrepancies in the observations by solving for constant changes, Δn i, and rates, i, in the mean motions of the four satellites. Earlier determinations of the values— primarily 1—have been based mainly on observations of ordinary eclipses that are much …