| Full text | |
| Author(s): |
Vieira, R. G.
[1]
;
Gregorio-Hetem, J.
[1]
;
Hetem, Jr., A.
[2]
;
Stasinska, G.
[3]
;
Szczerba, R.
[4]
Total Authors: 5
|
| Affiliation: | [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
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | Astronomy & Astrophysics; v. 526, FEB 2011. |
| Web of Science Citations: | 7 |
| Abstract | |
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) | |
| FAPESP's process: | 08/01533-4 - Circumstellar envelopes of intermediate mass young stars |
| Grantee: | Rodrigo Georgetti Vieira |
| Support type: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 05/00397-1 - Chemical evolution and galactic and extragalactic stellar populations by spectroscopy and imaging |
| Grantee: | Beatriz Leonor Silveira Barbuy |
| Support type: | Research Projects - Thematic Grants |