A gas giant planet just found to survived the death of its star

A crystal ball into our solar system's future.

Using W. M. Keck Observatory on Maunakea in Hawaii, astronomers have discovered a planetary system consisting of a Jupiter-like planet with a Jupiter-like orbit revolving around a white dwarf star. Lies about a quarter of the way towards the center of our Milky Way galaxy, the gas giant planet within the system just survived the death of its star.

The team also found that the planet avoided being destroyed after the death of its star. It means the Jupiter-like planet survived the death of its star without being gravitationally pinballed by other planets or stars.

Dr. Dimitri Veras of the University of Warwick’s Department of Physics said, “This planet just barely survived its star’s evolution. It is the first planet ever found at several astronomical units around a white dwarf, just short of the Jupiter-Sun distance. When I saw the numbers, I realized the importance of the discovery – we have finally seen a dynamically pristine planetary survivor.”

“This finding is a glimpse into the future of our solar system in a way that other discoveries are not. This planet appears to be untouched and unravaged by gravitational interactions with other large bodies, just as we think Jupiter will evolve when the Sun becomes a white dwarf.”

“We have now taken a crucial snapshot of a planet after its star transforms into a white dwarf. To attain a complete timeline of these systems, we need to take more snapshots at different ages.”

During the last stage of its life, the star burns off all hydrogen in its core. At last, it balloons into a red giant star and then collapses into itself, shrinking into a white dwarf.

Joshua Blackman, an astronomy postdoctoral researcher at the University of Tasmania in Australia and lead author of the study, said, “This evidence confirms that planets orbiting at a large enough distance can continue to exist after their star’s death. Given that this system is an analog to our solar system, it suggests that Jupiter and Saturn might survive the Sun’s red giant phase when it runs out of nuclear fuel and self-destructs.”

Co-author David Bennett, a senior research scientist at the University of Maryland and NASA’s Goddard Space Flight Center, said, “Earth’s future may not be so rosy because it is much closer to the Sun. If humankind wanted to move to a moon of Jupiter or Saturn before the Sun fried the Earth during its red supergiant phase, we’d remain in orbit around the Sun, although we would not be able to rely on heat from the Sun as a white dwarf for very long.”

For this discovery, the team used a technique called gravitational microlensing. When the team tried to look for the planet’s host star, they unexpectedly discovered the starlight wasn’t bright enough to be an ordinary, main-sequence star. The data also ruled out the possibility of a brown dwarf star as the host.

Co-author Jean-Philippe Beaulieu, Professor, Warren chair of Astrophysics at the University of Tasmania and Directeur de Recherche CNRS at the Institut d’Astrophysique de Paris said“We have also been able to rule out the possibility of a neutron star or a black hole host. This means that the planet is orbiting a dead star, a white dwarf. It offers a glimpse into what our solar system will look like after the disappearance of the Earth, whipped out in the cataclysmic demise of our Sun.”

Journal Reference:
  1. Blackman, J.W., Beaulieu, J.P., Bennett, D.P. et al. A Jovian analogue orbiting a white dwarf star. Nature 598, 272–275 (2021). DOI: 10.1038/s41586-021-03869-6



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