We propose a scenario to form low-mass, single, slow rotating white dwarfs from a solar-like star accompanied by a massive planet, or a brown dwarf, in a relatively close orbit (e.g. HD 89707). Such white dwarfs were recently found by Maxted & Marsh (1998). When the solar-like star ascends the giant branch it captures the planet and the subsequent spiral-in phase expels the envelope of the giant leaving a low-mass helium white dwarf remnant. In case the planet evaporizes, or fills its own Roche-lobe, the outcome is a single undermassive white dwarf. The observed distribution of planetary systems supports the applicability of this scenario.
@article{arxiv.astro-ph/9806011,
title = {Formation of undermassive single white dwarfs and the influence of planets on late stellar evolution},
author = {G. Nelemans and T. M. Tauris},
journal= {arXiv preprint arXiv:astro-ph/9806011},
year = {2007}
}