Periods Ranging from 5 to 1500 Days in the Anticorrelated Moving Lines of SS 433

Abstract

Some tens of harmonic components are found in the moving lines of SS 433, leaving a standard deviation of 0.002 in Z units, that is comparable to the observational error. Ten harmonics appear anticorrelated in the two branches, among which those at 80, 155, and 1500 days are also strong. Their behaviour indicates changing structure in the ejecting mechanism. No secular change is occurring in the precessional 163-day period beyond the estimated error of 5 × 10^-5d^-1. No periodicity occurs in beam velocity. One quarter of cases of (Z _l + Z ₂) are found outside their mean value by more than 5σ. This implies either variable beam velocity or absence of strict antiparallelism.