A Study of H alpha Line Profile Variations in beta Lyr

作者：Ignace Richard^*; Gray Sharon K; Magno Macon A; Henson Gary D; Massa Derck

来源：Astronomical Journal, 2018, 156(3): 97.

DOI：10.3847/1538-3881/aad339

• accretion, accretion disks
• binaries: eclipsing
• binaries: visual
• stars: early-type
• stars: individual (beta Lyr)

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 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.

• 出版日期2018-9