A Jovian analogue orbiting a white dwarf star

TL;DR

This paper reports the discovery of a Jupiter-mass planet orbiting a white dwarf star, providing evidence that such planets can survive stellar evolution, and supports the prediction that many white dwarfs host Jovian companions.

Contribution

First observational confirmation of a Jovian planet orbiting a white dwarf, demonstrating planetary survival through stellar evolution phases.

Findings

Detected a 1.4 Jupiter mass planet around a white dwarf.

System located approximately 2.0 kpc from Earth.

Supports theories predicting many white dwarfs have Jovian companions.

Abstract

Studies have shown that remnants of destroyed planets and debris-disk planetesimals can survive the volatile evolution of their host stars into white dwarfs, but detection of intact planetary bodies around white dwarfs are few. Simulations predict that planets in Jupiter-like orbits around stars of $\lt 8 M_\odot$ avoid being destroyed by the strong tidal forces of their stellar host, but as yet there has been no observational confirmation of such a survivor. Here we report on the non-detection of a main-sequence lens star in the microlensing event MOA-2010-BLG-477Lb using near-infrared observations from the Keck Observatory. We determine this system contains a $0.53\pm0.11$ solar mass white dwarf host orbited by a $1.4 \pm 0.3$ Jupiter mass planet with a separation on the plane of the sky of $2.8\pm 0.5$ AU, which implies a semi-major axis larger than this. This system is evidence that planets around white dwarfs can survive the giant and asymptotic giant phases of their host's evolution, and supports the prediction that over half of white dwarfs are predicted to have Jovian planetary companions. Located at approximately 2.0 kpc toward the center of our Galaxy, it likely represents an analog to the end stages of the Sun and Jupiter in our own Solar System.