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On the origin of the ultramassive white dwarf GD 50
journal contribution
posted on 2023-05-17, 14:35 authored by Dobbie, PD, Napiwotzki, R, Lodieu, N, Burleigh, MR, Barstow, MA, Jameson, RFWe argue on the basis of astrometric and spectroscopic data that the ultramassive white dwarf GD 50 is associated with the star formation event that created the Pleiades and is possibly a former member of this cluster. Its cooling age (∼60 Myr) is consistent with it having evolved essentially as a single star from a progenitor with a mass M > 6 M⊙, so we find no need to invoke a white dwarf–white dwarf binary merger scenario to account for its existence. This result may represent the first direct observational evidence that single-star evolution can produce white dwarfs with M > 1.1 M⊙, as predicted by some stellar evolutionary theories. On the basis of its tangential velocity, we also provisionally identify the ultramassive (M∼ 1.2 M⊙) white dwarf PG 0136 + 251 as being related to the Pleiades. These findings may help to alleviate the difficulties in reconciling the observed number of hot nearby ultramassive white dwarfs with the smaller number predicted by binary evolution models under the assumption that they are the products of white dwarf mergers.
History
Publication title
Monthly Notices of the Royal Astronomical SocietyVolume
373Pagination
L45-L49ISSN
1745-3933Department/School
School of Natural SciencesPublisher
Oxford University PressPlace of publication
United KingdomRights statement
Copyright 2006 the authors Journal compilation copyright RASRepository Status
- Restricted