A close encounter of the massive kind

We have used (i) Hubble Space Telescope Advanced Camera for Surveys imaging and Space Telescope Imaging Spectrograph spectroscopy, (ii) ground-based Precision Integrated-Optics Near-infrared Imaging ExpeRiment/Very Large Telescope long-baseline interferometry, and (iii) ground-based spectroscopy fro...

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Detalles Bibliográficos
Autores: Maíz Apellániz, Jesús, Sana, H., Barbá, R. H., Le Bouquin, J.-B., Gamen, R. C.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/214896
Acceso en línea:http://hdl.handle.net/10261/214896
Access Level:acceso abierto
Palabra clave:ephemerides
Binaries: visual
stars: individual: HD 93 129 Aa,Ab
stars: kinematics and dynamics: stars: winds, outflows
X-ray stars
Descripción
Sumario:We have used (i) Hubble Space Telescope Advanced Camera for Surveys imaging and Space Telescope Imaging Spectrograph spectroscopy, (ii) ground-based Precision Integrated-Optics Near-infrared Imaging ExpeRiment/Very Large Telescope long-baseline interferometry, and (iii) ground-based spectroscopy from different instruments to study the orbit of the extreme multiple system HD 93 129 Aa,Ab, which is composed of (at least) two very massive stars in a long-period orbit with e > 0.92, which will pass through periastron in 2017/2018. In several ways, the system is an ¿ Car precursor. Around the time of periastron passage, the two very strong winds will collide and generate an outburst of non-thermal hard X-ray emission without precedent in an O+O binary since astronomers have been able to observe above Earth's atmosphere. A coordinated multiwavelength monitoring in the next two years will enable a breakthrough understanding of the wind interactions in such extreme close encounters. Furthermore, we have found evidence that HD 93 129 Aa may be a binary system itself. In that case, we could witness a three-body interaction which may yield a runaway star or a stellar collision close to or shortly after the periastron passage. Either of those outcomes would be unprecedented, as they are predicted to be low-frequency events in the Milky Way.