On the evolutionary status of Be stars : I. Field Be stars near the Sun

A sample of 97 galactic field Be stars were studied by taking into account the effects induced by the fast rotation on their fundamental parameters. All program stars were observed in the BCD spectrophotometric system in order to minimize the perturbations produced by the circumstellar environment o...

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Detalles Bibliográficos
Autores principales: Zorec, J., Frémat, Y., Cidale, Lydia Sonia
Formato: Articulo
Lenguaje:Inglés
Publicado: 2005
Materias:
Ciencias Astronómicas
Stars: emission-line, Be
Stars: evolution
Stars: fundamental parameters (classification, colors, luminosities, masses, radii, temperatures, etc.)
Stars: rotation
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83293
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83293
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Stars: emission-line, Be
Stars: evolution
Stars: fundamental parameters (classification, colors, luminosities, masses, radii, temperatures, etc.)
Stars: rotation
spellingShingle Ciencias Astronómicas
Stars: emission-line, Be
Stars: evolution
Stars: fundamental parameters (classification, colors, luminosities, masses, radii, temperatures, etc.)
Stars: rotation
Zorec, J.
Frémat, Y.
Cidale, Lydia Sonia
On the evolutionary status of Be stars : I. Field Be stars near the Sun
topic_facet Ciencias Astronómicas
Stars: emission-line, Be
Stars: evolution
Stars: fundamental parameters (classification, colors, luminosities, masses, radii, temperatures, etc.)
Stars: rotation
description A sample of 97 galactic field Be stars were studied by taking into account the effects induced by the fast rotation on their fundamental parameters. All program stars were observed in the BCD spectrophotometric system in order to minimize the perturbations produced by the circumstellar environment on the spectral photospheric signatures. This is one of the first attempts at determining stellar masses and ages by simultaneously using model atmospheres and evolutionary tracks, both calculated for rotating objects. The stellar ages (τ) normalized to the respective inferred time that each rotating star can spend in the main sequence phase (τMS) reveal a mass-dependent trend. This trend shows that: a) there are Be stars spread over the whole interval 0 ≲ τ/τMS ≲ 1 of the main sequence evolutionary phase; b) the distribution of points in the (τ/τ MS,M/M⊙) diagram indicates that in massive stars (M ≳ 12 M⊙) the Be phenomenon is present at smaller τ/τMS age ratios than for less massive stars (M ≲ 12 M⊙). This distribution can be due to: i) higher mass-loss rates in massive objets, which can act to reduce the surface fast rotation; ii) circulation time scales to transport angular momentum from the core to the surface, which are longer the lower the stellar mass.
format Articulo
Articulo
author Zorec, J.
Frémat, Y.
Cidale, Lydia Sonia
author_facet Zorec, J.
Frémat, Y.
Cidale, Lydia Sonia
author_sort Zorec, J.
title On the evolutionary status of Be stars : I. Field Be stars near the Sun
title_short On the evolutionary status of Be stars : I. Field Be stars near the Sun
title_full On the evolutionary status of Be stars : I. Field Be stars near the Sun
title_fullStr On the evolutionary status of Be stars : I. Field Be stars near the Sun
title_full_unstemmed On the evolutionary status of Be stars : I. Field Be stars near the Sun
title_sort on the evolutionary status of be stars : i. field be stars near the sun
publishDate 2005
url http://sedici.unlp.edu.ar/handle/10915/83293
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AT cidalelydiasonia ontheevolutionarystatusofbestarsifieldbestarsnearthesun
bdutipo_str Repositorios
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