Spectrographic observations of the suspected delta scuti variable beta ari

Three sets of spectra (in all 85 spectra) of the well-known standard and high eccentricity spectroscopic binary star Beta Ari were taken with the Boller and Chivens grating spectrography (29 and 35 Å mm^?1) applied to the 137 cm reflector of the Merate Astronomical Observatory. These sets were takenduring the periastron passage of 14–15 November 1976,after the periastron passage of 2–3 October 1977 and before the apastron passage of 23 November 1977. The analysis of the radial velocitiesRV and equivalent widthsW _λ of hydrogen and metal lines show periodic variations similar to those of some classical Delta Scuti stars. The variations of the asymmetries of the profiles of H and Caii K lines, linked to the variations of theRV seem to recall the Schuster effect observed in classical Cepheids. A periastron effect appears from: (a) increased amplitudes of theRV curves, (b) remarkable variations of the averagedW _λ curves, (c) strong positive asymmetry (blue wing larger than red wing) in the Hγ and Caii K lines. A faint ‘bump’ inRV andW _λ curves of Caii K line is singled out and could be in agreement with some theoretical forecasts of Aleshin (1964).