Discovery of the Richest Pulsating Ultramassive White Dwarf

The discovery of pulsations in ultramassive (UM) white dwarfs (WDs) can help to probe their interiors and unveil their core composition and crystallized mass fraction through asteroseismic techniques. To date, the richest pulsating UM WD known is BPM 37093 with 8 modes detected, for which detailed a...

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Detalles Bibliográficos
Autores: De Gerónimo, Francisco César, Uzundag, Murat, Rebassa-Mansergas, Alberto, Brown, A., Kilic, Mukremin, Córsico, Alejandro H., Jewett, Gracyn C., Moss, Adam G.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/385346
Acceso en línea:http://hdl.handle.net/10261/385346
https://api.elsevier.com/content/abstract/scopus_id/85217234264
Access Level:acceso abierto
Palabra clave:White dwarf stars
Stellar oscillations
ZZ Ceti stars
Descripción
Sumario:The discovery of pulsations in ultramassive (UM) white dwarfs (WDs) can help to probe their interiors and unveil their core composition and crystallized mass fraction through asteroseismic techniques. To date, the richest pulsating UM WD known is BPM 37093 with 8 modes detected, for which detailed asteroseismic analysis has been performed in the past. In this work, we report the discovery of 19 pulsation modes in the UM WD star WD J0135+5722, making it the richest pulsating hydrogen-atmosphere UM WD known to date. This object exhibits multiperiodic luminosity variations with periods ranging from 137 to 1345 s, typical of pulsating WDs in the ZZ Ceti instability strip, which is centered at Teff ∼ 12,000 K. We estimate the stellar mass of WD J0135+5722 by different methods, resulting in M⋆ ∼ 1.12-1.14 M⊙ if the star’s core is made of oxygen and neon or M⋆ ∼ 1.14-1.15 M⊙ if the star hosts a carbon oxygen core. Future analysis of the star periods could shed light on the core chemical composition through asteroseismology.