A new magnetic white dwarf : PG2329+267

TL;DR

This paper reports the discovery of a magnetic white dwarf PG 2329+267 with a 2.3MG magnetic field, exhibiting Zeeman effects and polarization, suggesting it is more massive and likely evolved from magnetic Ap/Bp stars.

Contribution

The paper presents the first detailed magnetic field measurement and polarization analysis of PG 2329+267, a white dwarf, indicating its higher mass and evolutionary link to magnetic main sequence stars.

Findings

Magnetic field strength of approximately 2.3MG

Detection of Zeeman splitting and polarization effects

Indication that PG 2329+267 is more massive than typical white dwarfs

Abstract

We have discovered that the white dwarf PG 2329+267 is magnetic, and assuming a centered dipole structure, has a dipole magnetic field strength of approximately 2.3MG. This makes it one of only approximately 4% of isolated white dwarfs with a detectable magnetic field. Linear Zeeman splitting as well as quadratic Zeeman shifts are evident in the hydrogen Balmer sequence and circular spectropolarimetry reveals 10% circular polarisation in the two displaced sigma components of Halpha. We suggest from comparison with spectra of white dwarfs of known mass that PG 2329+267 is more massive than typical isolated white dwarfs, in agreement with the hypothesis that magnetic white dwarfs evolve from magnetic chemically peculiar Ap and Bp type main sequence stars.