B fields in OB stars (BOB): The magnetic triple stellar system HD 164492C in the Trifid nebula
HD 164492C is a spectroscopic triple stellar system that has beenrecently detected to possess a strong magnetic field. We have obtainedhigh-resolution spectroscopic and spectropolarimetric observations overa timespan of two years and derived physical, chemical, and magneticproperties for this object...
| Autores: | , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/63184 |
| Acceso en línea: | http://hdl.handle.net/11336/63184 |
| Access Level: | acceso abierto |
| Palabra clave: | STARS: EARLY TYPE BINARIES: SPECTROSCOPIC STARS: MAGNETIC FIELDS STARS: ABUNDANCES STARS: FUNDAMENTAL PARAMETERS STARS: INDIVIDUAL: HD 164492C https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Sumario: | HD 164492C is a spectroscopic triple stellar system that has beenrecently detected to possess a strong magnetic field. We have obtainedhigh-resolution spectroscopic and spectropolarimetric observations overa timespan of two years and derived physical, chemical, and magneticproperties for this object. The system is formed by an eccentric closespectroscopic binary (Ca1-Ca2) with a period of 12.5 days, and a massivetertiary Cb. We calculated the orbital parameters of the close pair,reconstructed the spectra of the three components, and determinedatmospheric parameters and chemical abundances by spectral synthesis.From spectropolarimetric observations, multi-epoch measurements of thelongitudinal magnetic fields were obtained. The magnetic field isstrongly variable on timescales of a few days, with a most probableperiod in the range of 1.4-1.6 days. Star Cb with T<sub>eff</sub>? 25 000 K is the apparently fastest rotator and the most massivestar of this triple system and has anomalous chemical abundances with amarked overabundance of helium, 0.35±0.04 by number. Weidentified this star as being responsible for the observed magneticfield, although the presence of magnetic fields in the components of theCa pair cannot be excluded. Star Ca1 with a temperature of about 24 000K presents a normal chemical pattern, while the least massive star Ca2is a mid-B type star (T<sub>eff</sub> ? 15 000 K) with anoverabundance of silicon. The obtained stellar parameters of the systemcomponents suggest a distance of 1.5 kpc and an age of 10-15 Myr. |
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