| Texto completo | |
| Autor(es): |
Perottoni, Helio D.
[1]
;
Amarante, Joao A. S.
[2]
;
Limberg, Guilherme
[1]
;
Rocha-Pinto, Helio J.
[3]
;
Rossi, Silvia
[1]
;
Anders, Friedrich
[4]
;
Borbolato, Lais
[1]
Número total de Autores: 7
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Astron, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Cent Lancashire, Jeremiah Horrocks Inst, Preston PR1 2HE, Lancs - England
[3] Univ Fed Rio de Janeiro, Observ Valongo, Lad Pedro Antonio 43, BR-20080090 Rio De Janeiro - Brazil
[4] Univ Barceloana IEEC UB, Inst Ciencies Cosmos, Carrer Marti i Franques 1, E-08028 Barcelona - Spain
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Astrophysical Journal Letters; v. 913, n. 1 MAY 2021. |
| Citações Web of Science: | 0 |
| Resumo | |
Planets and their host stars carry a long-term memory of their origin in their chemical compositions. Thus, identifying planets formed in different environments improves our understating of planetary formation. Although restricted to detecting exoplanets within the solar vicinity, we might be able to detect planetary systems that formed in small external galaxies and later merged with the Milky Way. In fact, Gaia data have unequivocally shown that the Galaxy underwent several significant minor mergers during its first billion years of formation. The stellar debris of one of these mergers, Gaia-Enceladus (GE), is thought to have built up most of the stellar halo in the solar neighborhood. In this Letter, we investigate the origin of known planet-host stars combining data from the NASA Exoplanet Archive with Gaia EDR3 and large-scale spectroscopic surveys. We adopt a kinematic criterion and identify 42 stars associated with the Milky Way's thick disk and one halo star. The only halo star identified, BD+20 2457, known to harbor two exoplanets, moves on a retrograde and highly eccentric orbit. Its chemical abundance pattern situates the star at the border between the thick disk, the old halo, and accreted populations. Given its orbital parameters and chemical properties, we suggest that BD+20 2457 is likely formed in the protodisk of the Galaxy, but we do not exclude the possibility of the star belonging to the debris of GE. Finally, we estimate a minimum age and mass limit for the star, which has implications for its planetary system and will be tested with future Transiting Exoplanet Survey Satellite observations. (AU) | |
| Processo FAPESP: | 14/18100-4 - Populações estelares na Via Láctea: bojo, halo, disco e regiões de formação de estrelas; instrumentação para espectroscopia de alta resolução |
| Beneficiário: | Beatriz Leonor Silveira Barbuy |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 15/50374-0 - Mosaic: the multi-object spectrograph for the ESO Extremely Large Telescope |
| Beneficiário: | Silvia Cristina Fernandes Rossi |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 18/21250-9 - Identificação de estrelas brilhantes pobres em metais a partir de fotometria Multi-Banda e acompanhamento espectroscópico |
| Beneficiário: | Hélio Dotto Perottoni |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |