A new extremely low-mass white dwarf in the NLTT catalogue

Abstract

We report on the discovery of the extremely low-mass, hydrogen-rich white dwarf, NLTT 11748. Based on measurements of the effective temperature (8540+/-50 K) and surface gravity (log g = 6.20+/-0.15) obtained by fitting the observed Balmer line profiles with synthetic spectra, we derive a mass of 0.167+/-0.005 M_solar. This object is one of only a handful of white dwarfs with masses below 0.2 M_solar that are believed to be the product of close binary evolution with an episode of Roche lobe overflow onto a degenerate companion (neutron star or white dwarf). Assuming membership in the halo population, as suggested by the kinematics and adopting a cooling age of 4.0 - 6.3 Gyrs for the white dwarf, we infer a progenitor mass of 0.87 - 0.93 M_solar. The likely companion has yet to be identified, but a search for radial velocity variations may help constrain its nature.

Accepted for publication in A&A Letters

References in corpus (5)

• The masses of PSR J1911-5958A and its white dwarf companion
• The Future is Now: the Formation of Single Low Mass White Dwarfs in the Solar Neighborhood
• The Discovery of a Companion to the Lowest Mass White Dwarf
• LP 400-22, A very low-mass and high-velocity white dwarf
• The Runaway White Dwarf LP400-22 Has a Companion

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