| Issue |
A&A
Volume 709, May 2026
|
|
|---|---|---|
| Article Number | A167 | |
| Number of page(s) | 5 | |
| Section | Stellar structure and evolution | |
| DOI | https://doi.org/10.1051/0004-6361/202659678 | |
| Published online | 13 May 2026 | |
The Be star o Cas is indeed the primary of a triple system
1
Astronomical Institute of Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, CZ-180 00 Praha 8, Troja, Czech Republic
2
Department of Physics and Astronomy, University of Victoria, P.O. Box 1700, STN CSC, Victoria, BC V8W 2Y2, Canada
3
Astronomical Institute, Czech Academy of Sciences, CZ-251 65 Ondřejov, Czech Republic
4
Vanderbilt University, Nashville, Tennessee, USA
5
Observatório Astronómico do Centro de Informação Geoespacial do Exército, Lisboa, Portugal
6
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
3
March
2026
Accepted:
15
April
2026
Abstract
Analysis of radial velocities of two narrow absorption components in the Mg II 4481 Å line demonstrated that the secondary of the Be star o Cas is indeed a close binary system composed of two B7 stars orbiting each other with a period of 11.″6604. Orbital solutions and spectral disentangling lead to consistent system properties. The system is extremely important for the research of Be stars since its future interferometric observations with a high spatial resolution could allow the mass and perhaps even the radius of a Be star to be derived without too many model assumptions, mainly on the dynamical grounds.
Key words: binaries: spectroscopic / stars: emission-line / Be / stars: fundamental parameters / stars: individual: o Cas
© The Authors 2026
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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