A Study of H$\alpha$ Line Profile Variations in $\beta$ Lyr

Abstract

We examine over 160 archival H$\alpha$ spectra from the Ritter Observatory for the interacting binary $\beta$~Lyr obtained between 1996 and 2000. The emission is characteristically double-peaked, but asymmetric, and with an absorption feature that is persistently blueshifted. Using a set of simplifying assumptions, phase varying emission line profiles are calculated for H$\alpha$ formed entirely in a Keplerian disk, and separately for the line formed entirely from an off-center bipolar flow. However, a dynamic spectrum of the data indicate the blueshifted feature is not always present, and the data are even suggestive of a drift of the feature in velocity shift. We explore whether a circumbinary envelope, hot spot on the accretion disk, or accretion stream could explain the observations. While none are satisfactory, an accretion stream explanation is somewhat promising.

arXiv commentaccepted to Astronomical Journal

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Cited by in corpus (2)

• Optically thin circumstellar medium in $\beta$ Lyr A system
• The GALAH survey: Characterization of emission-line stars with spectral modelling using autoencoders