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arXiv · 2609.21852

Orbital and stellar parameter determination of eclipsing $β$ Cep pulsators

C. I. Eze·G. Handler·F. Kahraman Aliçavuş·T. Pawar·P. De Cat
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Abstract

Eclipsing binaries provide precise constraints on stellar properties and evolution, making those hosting $β$ Cep pulsators particularly valuable for characterising massive pulsating stars. In this paper, thirteen eclipsing binaries with massive primary components are spectroscopically and photometrically analysed to derive the orbital and stellar parameters, and infer their possible evolutionary status. The systems were spectroscopically observed using SALT HRS, HERMES, CHIRON and a spectrograph at Skalnate Pleso Observatory (SPO), and photometrically observed using TESS. Radial velocities and atmospheric parameters are determined, binary systems are modelled, and their absolute parameters are derived using appropriate modelling tools. The rotational properties, circularisation, and synchronisation of the systems are also investigated, and the general properties of the sample are discussed. The sample shows one slow rotator, two circularised and synchronised fast rotating systems, as well as five circular and five eccentric systems with asynchronous fast rotation. The systems are predominantly SB1 or SB2 with faint companions, resulting in dynamical mass estimates at $5$ -- $12\%$ precision and radius estimates at $1.5$ -- $3.9\%$ precision. The secondary components appear to cut across a wide mass spectrum ranging from low-mass to intermediate mass systems. The eccentricity of the systems shows certain trends with the projected rotational velocity ($v \sin i$) although there is no universal correlation between them. Also, there could be circularisation without co-rotation or synchronisation even for circularised short-period close binary systems.

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C. I. Eze, G. Handler, F. Kahraman Aliçavuş, T. Pawar, P. De Cat. 2026-09-18. Orbital and stellar parameter determination of eclipsing $β$ Cep pulsators. https://arxiv.org/abs/2609.21852

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