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The evolutionary stage of five southern Galactic unclassified B[e] stars

Published online by Cambridge University Press:  26 May 2016

Marcelo Borges Fernandes
Affiliation:
Observatório National, Rua General José Cristino 77, CEP: 20921-400, São Cristóvão, Rio de Janeiro, Brasil Sterrekundig Instituut, Universiteit Utrecht, Princetonplein 5, NL-3584 CC Utrecht, Nederland
Francisco X. de Araújo
Affiliation:
Observatório National, Rua General José Cristino 77, CEP: 20921-400, São Cristóvão, Rio de Janeiro, Brasil
H. Lamers
Affiliation:
Sterrekundig Instituut, Universiteit Utrecht, Princetonplein 5, NL-3584 CC Utrecht, Nederland

Abstract

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The spectra of stars with the B[e] phenomenon are dominated by features that are related to physical conditions of circumstellar material around these objects and are not intrinsic to the stars. Because of this, they form a very heterogeneous group. This group contains objects with different evolutionary stages. Lamers et al. (1998) have suggested a new designation with five sub-groups, which indicate the evolutionary stage. They are: supergiants, pre-main sequence or Herbig Ae/Be, compact planetary nebulae, symbiotic and unclassified. The unclassified group has many objects that need a better study to resolve their evolutionary status. Forbidden lines can be a useful tool to solve this problem. They can give informations about chemical composition, ionization and density of the circunstellar medium and probably the evolutionary phase of these objects. We analize spectra of some galactic objects, obtained with the feros and b&c spectrographs at the 1.52m telescope in ESO (La Silla-Chile), with a special focus on the forbidden lines. We have studied the spectra of five B[e] stars of uncertain evolutionary stage. We find that one of them is a pre-WN star, the other four are supergiant B[e] stars.

Type
Part 1. Atmospheres of Massive Stars
Copyright
Copyright © Astronomical Society of the Pacific 2003 

References

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