PHL 5038AB: is the brown dwarf causing pollution of its white dwarf host star?

We present new results on PHL 5038AB, a widely separated binary system composed of a white dwarf and a brown dwarf, refining the white and brown dwarf parameters and determining the binary separation to be au. New spectra of the white dwarf show calcium absorption lines suggesting that the hydrogen-...

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Detalhes bibliográficos
Autores: Casewell, Sarah, Debes, John J., Dupuy, Trent J., Dufour, Pierre, Bonsor, Amy, Rebassa Mansergas, Alberto|||0000-0002-6153-7173, Murillo Ojeda, Raquel
Formato: artículo
Fecha de publicación:2024
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/426922
Acesso em linha:https://hdl.handle.net/2117/426922
https://dx.doi.org/10.1093/mnras/stae974
Access Level:acceso abierto
Palavra-chave:Brown dwarfs
stars: Low-mass
White dwarfs
Infrared: stars
Descrição
Resumo:We present new results on PHL 5038AB, a widely separated binary system composed of a white dwarf and a brown dwarf, refining the white and brown dwarf parameters and determining the binary separation to be au. New spectra of the white dwarf show calcium absorption lines suggesting that the hydrogen-rich atmosphere is weakly polluted, inferring the presence of planetesimals in the system, which we determine are in an S-type orbit around the white dwarf in orbits closer than 17–32 au. We do not detect any infrared excess that would indicate the presence of a disc, suggesting that all dust present either has been totally accreted or is optically thin. In this system, we suggest that the metal pollution in the white dwarf atmosphere can be directly attributed to the presence of the brown dwarf companion disrupting the orbits of planetesimals within the system.