| Texto completo | |
| Autor(es): |
Vieira, R. G.
[1]
;
Gregorio-Hetem, J.
[1]
;
Hetem, Jr., A.
[2]
;
Stasinska, G.
[3]
;
Szczerba, R.
[4]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil
[2] Univ Fed ABC, CECS, BR-09210170 Santo Andre, SP - Brazil
[3] Observ Meudon, LUTH, F-92190 Meudon - France
[4] Nicholas Copernicus Astron Ctr, PL-87100 Torun - Poland
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Astronomy & Astrophysics; v. 526, FEB 2011. |
| Citações Web of Science: | 7 |
| Resumo | |
Context. A sample of 27 sources, cataloged as pre-main sequence stars by the Pico dos Dias Survey (PDS), is analyzed to investigate a possible contamination by post-AGB stars. The far-infrared excess due to dust present in the circumstellar envelope is typical of both categories: young stars and objects that have already left the main sequence and are suffering severe mass loss. Aims. The two known post-AGB stars in our sample inspired us to seek for other very likely or possible post-AGB objects among PDS sources previously suggested to be Herbig Ae/Be stars, by revisiting the observational database of this sample. Methods. In a comparative study with well known post-AGBs, several characteristics were evaluated: (i) parameters related to the circumstellar emission; (ii) spatial distribution to verify the background contribution from dark clouds; (iii) spectral features; and (iv) optical and infrared colors. Results. These characteristics suggest that seven objects of the studied sample are very likely post-AGBs, five are possible post-AGBs, eight are unlikely post-AGBs, and the nature of seven objects remains unclear. (AU) | |
| Processo FAPESP: | 05/00397-1 - Evolução química e populações estelares galáctica e extragalácticas por espectroscopia e imageamento |
| Beneficiário: | Beatriz Leonor Silveira Barbuy |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 08/01533-4 - Envoltórios circunstelares de estrelas jovens de massa intermediária |
| Beneficiário: | Rodrigo Georgetti Vieira |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |