A fast spinning magnetic white dwarf in the double degenerate, super-Chandrasekhar system NLTT 12758

Author(s)
Adela Kawka, Gordon P. Briggs, Stephane Vennes, Ernst Paunzen
Abstract

We present an analysis of the close double degenerate NLTT 12758, which is comprised of a magnetic white dwarf with a field of about 3.1 MG and an apparently non-magnetic white dwarf. We measured an orbital period of 1.154 d and found that the magnetic white dwarf is spinning around its axis with a period of 23 min. An analysis of the atmospheric parameters has revealed that the cooling ages of the two white dwarfs are comparable, suggesting that they formed within a short period of time from each other. Our modelling indicates that the non-magnetic white dwarf is more massive (M = 0.83 M) than its magnetic companion (M = 0.69 M) and that the total mass of the system is higher than the Chandrasekhar mass. Although the stars will not come into contact over a Hubble time, when they do come into contact, dynamically unstable mass transfer will take place leading to either an accretion induced collapse into a rapidly spinning neutron star or a Type Ia supernova.

Organisation(s)
Department of Astrophysics
External organisation(s)
Czech Academy of Sciences, Australian National University, Masaryk University
Journal
Monthly Notices of the Royal Astronomical Society
Volume
466
Pages
1127 - 1139
No. of pages
13
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stw3149
Publication date
04-2017
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/fbac9c1b-af88-4f24-983b-7b045385c573