The white dwarf binary pathways survey - IX. Three long period white dwarf plus subgiant binaries
Virtually all binaries consisting of a white dwarf with a non-degenerate companion can be classified as either close post-interaction systems (with orbital periods of a few days or less), or wide systems (with periods longer than decades), in which both components have effectively evolved as single...
| Autores: | , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/446865 |
| Acceso en línea: | https://hdl.handle.net/2117/446865 https://dx.doi.org/10.1093/mnras/stac3368 |
| Access Level: | acceso abierto |
| Palabra clave: | White dwarf binaries Orbital periods Common envelope evolution Subgiant companions Hubble Space Telescope spectroscopy Low mass white dwarfs Hierarchical triple system Stable mass transfer Binary mergers Compact binary formation. Àrees temàtiques de la UPC::Física::Astronomia i astrofísica |
| Sumario: | Virtually all binaries consisting of a white dwarf with a non-degenerate companion can be classified as either close post-interaction systems (with orbital periods of a few days or less), or wide systems (with periods longer than decades), in which both components have effectively evolved as single stars. Binaries with periods between these two extremes can help constrain common envelope efficiency, or highlight alternative pathways towards the creation of compact binaries. To date such binaries have remained mostly elusive. Here we present three white dwarfs in binaries with evolved subgiant stars with orbital periods of 41, 52, and 461¿d. Using Hubble Space Telescope spectroscopy we find that all three systems contain low mass white dwarfs (=0.4¿M¿). One system, TYC¿8394-1331-1, is the inner binary of a hierarchical triple, where the white dwarf plus subgiant binary is orbited by a more distant companion star. These binaries were likely formed from a phase of stable but non-conservative mass transfer, as opposed to common envelope evolution. All three systems will undergo a common envelope phase in the future, but the two shorter period systems are expected to merge during this event, while the longest period system is likely to survive and create a close binary with two low mass white dwarfs. |
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