1998/02/10 by Eric J. Bakker, Bakker, Eric J., David L. Lambert +11
Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9802120
14 pages + 8 pages appendix, 17 figures, 4 tables A&A accepted
arxiv created 1998/02/10 · openalex publication_date 1998/02/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Hα profile varies with the orbital period. The two strong shell type emission peaks are identified as from one single broad emission feature with an absorption centered around -7.5~\kms. The intensity variations are largely attributed to a differential amount of reddening towards the Hα emitting region and the stellar continuum. The radial velocities suggest that the Hα emission moves in phase with the primary, but with a slightly lower velocity amplitude. We propose two competing models that could account for the observed velocity and intensity variations of the Hα profile. Model I: light from the primary reflects on a localized spot near the inner radius of the circumbinary disc which is closest to the primary. Model II: Hα emission originates in the outer layers of the extended atmosphere of the primary due to activity. These activities are locked to the position of the primary in its orbit. We discuss the similarities of variability and shape of the Hα emission of HR~4049 with those of early type T-Tauri stars (e.g SU~Aur).