Structural and Kinematic Features of the Gaseous Envelope of the Unusual Herbig Ae Star HD 179218 II. Long-term Spectral and Photometric Variability

This paper is the second in a series of papers dedicated to the analysis of spectral and photometric observations of the Herbig Ae/Be star HD 179218. The variations in the H $$\alpha$$ and H $$\beta$$ line profiles in the star’s spectrum and the variations in its brightness and color indices in the $$UBVRI$$ system are investigated. Regular variations of the profiles with periods from 37 to 737 days at a significance level of $$10^{-4}$$ were revealed. Two of the found spectral periods agree with the photometric ones within the error limits. The regular spectral and photometric variability we discovered may indicate a presence of a companion or an exoplanet/exoplanets around the star, and may also be associated with the precession of the accretion disk and variation of the accretion rate.