A Young White Dwarf with an Infrared Excess

TL;DR

This paper reports the discovery of infrared excess around a young, hot white dwarf, suggesting the presence of a dust disk or substellar object, with unique properties distinguishing it from typical white dwarf systems.

Contribution

It presents the first detection of infrared excess in a very young, hot white dwarf and explores possible origins, including a dust disk or irradiated substellar companion.

Findings

Infrared excess detected at 3-8 μm in a young white dwarf.

The excess can be modeled by a dust disk or a hot blackbody.

The white dwarf shows low emission at 8 μm and no heavy elements in its atmosphere.

Abstract

Using observations of Spitzer/IRAC, we report the serendipitous discovery of excess infrared emission from a single white dwarf PG 0010+280. At a temperature of 27,220 K and a cooling age of 16 Myr, it is the hottest and youngest white dwarf to display an excess at 3-8 $\mu$m. The infrared excess can be fit by either an opaque dust disk within the tidal radius of the white dwarf or a 1300 K blackbody, possibly from an irradiated substellar object or a re-heated giant planet. PG 0010+280 has two unique properties that are different from white dwarfs with a dust disk: (i) relatively low emission at 8 $\mu$m and (ii) non-detection of heavy elements in its atmosphere from high-resolution spectroscopic observations with Keck/HIRES. The origin of the infrared excess remains unclear.