Discovery of a uniquely cool and compact source at 28 parsecs from the Sun

TL;DR

This paper reports the discovery of a potentially unique, extremely old and cool white dwarf within 30 parsecs of the Sun, identified through multi-survey data and characterized by its low luminosity and spectral energy distribution.

Contribution

It introduces a new candidate white dwarf with unusual properties, expanding knowledge of old stellar remnants in the solar neighborhood.

Findings

Identified a candidate white dwarf at 28 parsecs with unique spectral features.

Suggests the object is an extremely old, cool white dwarf with a helium atmosphere.

Highlights the need for spectroscopic follow-up to confirm its nature.

Abstract

We present the discovery of what appears to be both a uniquely cool and old white dwarf within 30 parsecs of the sun. DES J214756.46-403529.3 is detected in four separate surveys, 50 degrees away from the Galactic Plane. The combination of its very low luminosity and spectral energy distribution suggests an object unlike any other astrophysical body currently known. Among 8,000 of the nearest single objects in the immediate solar neighbourhood, it appears completely isolated in multiple colour-magnitude diagrams. The data seem compatible with an extremely old and cool white dwarf with a helium dominated atmosphere and a mass around 0.7-0.8\,\msun\ but spectroscopic follow-up is required to confirm its nature.