Pulsations of the sun and a beat period of 399 days

Abstract

Measurements of the Doppler effect of the solar photosphere have been carried out at the Crimean Astrophysical Observatory for 37 years, beginning in 1974 (in total, 2188 days or 13 247 h). The measurements use the differential center-to-limb method of registration of line-of-sight velocity with a solar magnetograph (in the iron absorption line λ512.4 nm). As a result of the experiment, two global pulsations of the sun with periods P ₀ = 9600.606(12) and P ₁ = 9597.936(16) s have been discovered. The nature of the periods is unknown. The first pulsation was detected in 1974–1982; the second, during nearly all the 37 years. The 2008–2010 data confirm the stability of the initial phase of the P ₁ pulsation with a mean (differential) amplitude of 0.25 m/s. The fact that the beat period of the two pulsations coincides with the synodic period of Jupiter’s orbital revolution, i.e., 399 days, raises a new, complex problem for solar physics and cosmogony.