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Interpretation of the variability of the β Cephei star λ Scorpii. I. The multiple character

Uytterhoeven, K.; Willem, B.; Lefever, K.; Aerts, C.; Telting, J. H. and Kolb, U. (2004). Interpretation of the variability of the β Cephei star λ Scorpii. I. The multiple character. Astronomy and Astrophysics, 427 pp. 581–592.

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DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1051/0004-6361:20041223
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Abstract

We derive accurate values of the orbital parameters of the close binary β Cephei star λ Scorpii. Moreover, we present the first determination of the properties of the triple system to which λ Scorpii belongs. Our analysis is based on a time series of 815 high-resolution spectra, covering a timespan of 14 years. We find a close orbit of 5d.9525days (e=0.26) and a wide orbit of approximately 1082d days (e=0.23). The orbital parameters of the triple star and a spectrum synthesis lead us to conclude that the system is composed of two early-type B stars and a low-mass pre-main-sequence star rather than containing an ultra-massive white dwarf as claimed before. Our proposed configuration is compatible with population synthesis. The radial velocity variations of the primary allow us to confirm the presence of at least one pulsation mode with frequency 4.679410 c d-1 which is subject to the light-time effect in the triple system. A detailed analysis of the complex line-profile variations is described in a subsequent paper. Based on observations obtained with the Coudé Echelle Spectrograph on the ESO CAT telescope and with the CORALIE Echelle Spectrograph on the 1.2-m Euler Swiss telescope, both situated at La Silla, Chile Table \ref{observations} is only available in electronic form at http://www.edpsciences.org

Item Type: Journal Article
Copyright Holders: 2004 ESO
ISSN: 1432-0746
Project Funding Details:
Funded Project NameProject IDFunding Body
Not SetNot SetNASA ATP [grant NAG5-13236]
Not SetNot SetK.U. Leuven Fund [grant GOA/2003/04]
Extra Information: Article published by EDP Sciences
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
eSTEeM
Item ID: 6068
Depositing User: Christopher Biggs
Date Deposited: 20 Dec 2006
Last Modified: 07 Mar 2014 20:48
URI: http://oro.open.ac.uk/id/eprint/6068
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