title: Be binary stars with hot, compact companions
creator: Maintz, Monika
subject: ddc-520
subject: 520 Astronomy and allied sciences
description: In this study the importance of close binary evolution for Be star formation was investigated. The Be star 59 Cygni was confirmed to be an evolved binary with a sdO companion. The companion was confirmed by a weak helium II absorption. Orbital elements and stellar masses were determined. In the spectrum of 59 Cygni, characteristic features were identified. These are a single-peaked emission component, a phase-locked V/R variability, and a "knotty" structure of the absorption lines. According to Stefl et al. (2000), these features are caused by a hot, compact companion (sdO or WD) that photoionizes a sector of the disc of the Be star. Assuming this model and a code of Hummel and Stefl (2001) the emission variability of 59 Cygni was successfully reproduced. The features, observed in the spectrum of 59 Cygni, were confirmed for the Be+sdO binary phi Persei and for HR2142, too. Hence, these features were taken as indicators for Be binaries with hot, compact companions. HR2142 was confirmed to be a Be+sdO binary. The spectral variability of further candidates was examined. It was suggested that FY CMa is a Be+sdO binary and that kappa Draconis is a Be+WD binary. The assumption that a fraction of the Be stars formed by mass and angular momentum transfer in close binary systems was confirmed.
date: 2003
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/4343/1/Monika_Maintz_Dissertation.pdf
identifier: DOI:10.11588/heidok.00004343
identifier: urn:nbn:de:bsz:16-opus-43435
identifier:   Maintz, Monika  (2003) Be binary stars with hot, compact companions.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/4343/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng