We examine over 160 archival Hα spectra from the Ritter Observatory for the interacting binary β 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 Hα 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 indicates that 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.
Ignace, Richard; Gray, Sharon K.; Magno, Macno A.; Henson, Gary D.; and Massa, Derek. 2018. A Study of Hα Line Profile Variations in β Lyr. The Astronomical Journal. Vol.156(97). https://doi.org/10.3847/1538-3881/aad339 ISSN: 0004-6256
Reproduced by permission of the AAS.