2024-03-29T13:40:09Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1338322017-06-07T10:10:15Zcom_10261_97com_10261_4col_10261_350
The little-studied cluster Berkeley 90: I. LS III +46 11: A very massive O3.5 If∗ + O3.5 If∗ binary
Maíz Apellániz, Jesús
Negueruela, I.
Barbá, R. H.
Walborn, N. R.
Pellerin, A.
Simon-Diaz, S.
Sota Ballano, Alfredo
Marco, A.
Alonso-Santiago, J.
Sánchez Bermúdez, Joel
Gamen, R. C.
Lorenzo, J.
Gobierno de Canarias
Generalitat Valenciana
Consejo Superior de Investigaciones Científicas (España)
National Aeronautics and Space Administration (US)
Ministerio de Economía y Competitividad (España)
European Commission
Junta de Andalucía
Stars: early-type
Binaries: spectroscopic
Dust, extinction
ISM: lines and bands
Stars: individual: LS III+46 11
Open clusters and associations: individual: Berkeley 90
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.
2016-06-21T10:50:25Z
2016-06-21T10:50:25Z
2015
2016-06-21T10:50:25Z
artículo
Astronomy and Astrophysics 579 (2015)
http://hdl.handle.net/10261/133832
10.1051/0004-6361/201526123
http://dx.doi.org/10.13039/501100003359
http://dx.doi.org/10.13039/501100003339
http://dx.doi.org/10.13039/100000104
http://dx.doi.org/10.13039/501100003329
http://dx.doi.org/10.13039/501100000780
http://dx.doi.org/10.13039/501100011011
eng
Publisher's version
Sí
info:eu-repo/grantAgreement/MINECO/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AYA2013-40611-P
openAccess
EDP Sciences