The prominent 1.6-year periodicity in solar motion due to the inner planets
Abstract. The solar motion due to the inner (terrestrial) planets (Mercury, Me; Venus, V; Earth, E; Mars, Ma) has been calculated (here for the years 1868–2030). The author found these basic properties of this motion: the toroidal volume in which the Sun moves has the inner radius of 101.3 km and the outer radius of 808.2 km. The solar orbit due to the inner (terrestrial) planets is "heart-shaped". The orbital points which are the closest to the centre lie at the time distance of 1.6 years (584 days), on the average, and approximately coincide with the moments of the oppositions of V and E. The spectrum of periods shows the dominant period of 1.6 years (V-E) and further periods of 2.13 years (E-Ma) (25.6 months, QBO), 0.91 years (V-Ma), 0.8 years ((V-E)/2) and 6.4 years. All the periods are above the 99% confidence level. A possible connection of this solar motion with the mid-term quasi-periodicities (MTQP, i.e. 1.5–1.7 years) in solar and solar-terrestrial indices can be proposed.