Lorenzo, J.; Sanchez Bermudez, J.; Gamen, R. C.; Alonso-Santiago, J.; Marco, A.; Sota, A.; Simón-Díaz, S.; Walborn, N. R.; Pellerin, A.; Barbá, R. H.; Negueruela, I.; Maíz Apellániz, J.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 579, id.A108, 12 pp.
Fecha de publicación:
7
2015
Revista
Número de citas
21
Número de citas referidas
20
Descripción
Context. It appears that most (if not all) massive stars are born in
multiple systems. At the same time, the most massive binaries are hard
to find owing to their low numbers throughout the Galaxy and the implied
large distances and extinctions. Aims: We want to study LS III
+46 11, identified in this paper as a very massive binary; another
nearby massive system, LS III +46 12; and the surrounding stellar
cluster, Berkeley 90. Methods: Most of the data used in this
paper are multi-epoch high S/N optical spectra, although we also use
Lucky Imaging and archival photometry. The spectra are reduced with
dedicated pipelines and processed with our own software, such as a
spectroscopic-orbit code, CHORIZOS, and MGB. Results: LS III +46
11 is identified as a new very early O-type spectroscopic binary [O3.5
If* + O3.5 If*] and LS III +46 12 as another early O-type system [O4.5
V((f))]. We measure a 97.2-day period for LS III +46 11 and derive
minimum masses of 38.80 ± 0.83 M⊙ and 35.60
± 0.77 M⊙ for its two stars. We measure the
extinction to both stars, estimate the distance, search for optical
companions, and study the surrounding cluster. In doing so, a variable
extinction is found as well as discrepant results for the distance. We
discuss possible explanations and suggest that LS III +46 12 may be a
hidden binary system where the companion is currently undetected.
Proyectos relacionados
Proyecto IACOB: Una Nueva Era en el Estudio de Estrellas OB Galácticas
Massive stars has been many times claimed as Cosmic Engines and Gifts of Nature for the study of the Universe, from the Solar neighbourhood to the large-z Universe. The complete understanding of the physical properties and evolution of massive stars (and their interplay with the ISM) is crucial for many fields of Astrophysics and, ultimately, to
Sergio
Simón Díaz