The future of the solar system seen: 1st planet around a white dwarf


The artist’s concept shows a white dwarf with a giant gas planet and debris in orbit. It is a glimpse into the future of the solar system. Image via WM Keck Observatory/ Adam Makarenko.

Scientists now have proof that some planets in our solar system can survive the death of our sun. They said on October 13, 2021 that they had found a star system – about 6500 light years away, towards the center of our Milky Way galaxy – made up of a star once like our sun but now a dwarf. compact white. This star is still orbiting a giant gas planet, similar in size and orbit to Jupiter, the large planet in our solar system. This is proof that Jupiter (at least) can and will survive when our own sun swells into a red giant, just before entering the white dwarf stage of evolution of stars. The newly discovered Jupiter-sized planet now surrounds the cold, scorched remnants of its star. And so, for the first time, we see the future of our own solar system, in about 5 billion years.

Astronomers published their study on October 13 in the Peer reviewed newspaper Nature.

Astronomers made the discovery with the WM Keck Observatory in Hawaii. Principal author Joshua Blackman from the University of Tasmania noted:

This evidence confirms that planets orbiting at a sufficiently large distance can continue to exist after the death of their star. Since this system is an analogue of our own solar system, this suggests that Jupiter and Saturn could survive the red giant phase of the sun, when it runs out of nuclear fuel and self-destructs.

The future of the solar system: outer planets versus inner planets

Scientists have long wondered if the outer planets would be safe from the star’s swollen red giant phase and stay for the long haul. Now they have proof that they will. But the prospects for Earth to exist beyond the red giant phase can be bleak. When the sun turns into a red giant, scientists expect it to swallow Mercury, Venus, and possibly Earth as well. Therefore, humanity will need an escape plan to survive. Co-author David Bennett from the University of Maryland and NASA’s Goddard Space Flight Center said:

The future of the Earth may not be so rosy because it is much closer to the sun. If humanity wanted to move to a moon of Jupiter or Saturn before the sun sintered the Earth during its red supergiant phase, we would still remain in orbit around the sun, although we could not rely on the heat of the Earth. sun like a white dwarf for a very long time.

Make the discovery

The sun is a main sequence Star. Main sequence stars are medium stars which, as they age, burn off their hydrogen and begin to develop into red giants. This is the red giant phase that can eat the living Earth, depending on its size before the sun collapses on itself and swells its outer layers. Then the sun sets in for the rest of its existence as a chilling white dwarf. A white dwarf is essentially a dead star.

A white dwarf is about the size of Earth with a mass about half that of the sun. Due to their small size and cool temperatures, they are dark and difficult to detect. The Keck telescope used a resolution close toinfrared imagery to spot this white dwarf and this planet. The gravitational microlens revealed the pair. Gravitational microlens it is when a near star aligns with a distant star. The nearest star acts like a lens, magnifying the light from the farthest star.

Scientists noticed a deformation of the star’s lens light, and this is what led to the discovery of the exoplanet. The white dwarf makes up about 60% of the mass of our sun. Its exoplanet is about 40% more massive than Jupiter. Due to its penumbra, scientists have ruled out that the light of this star comes from a main sequence star or a brown dwarf. Co-author Jean-Philippe Beaulieu from the University of Tasmania explained:

We were also able to rule out the possibility of a neutron star or black hole host. This means that the planet is orbiting a dead star, a white dwarf. It offers a glimpse of what our solar system will look like after Earth’s demise, caused by the cataclysmic demise of our sun.

Future research

Scientists are using their new data to find out how many other planets have survived and are orbiting white dwarfs. the Nancy Grace Roman Telescope, scheduled for launch in the middle of this decade, will be able to directly image giant planets. The Roman Space Telescope is expected to be able to study planets orbiting white dwarfs as far as the galactic bulge. John O’Meara of Keck Observatory summed it up as follows:

It is an extremely exciting result. It’s wonderful to see today an example of the kind of science Keck will do en masse when Roman begins his mission.

Conclusion: Scientists got a glimpse of the future of the solar system when they discovered a giant gas planet orbiting a white dwarf. One day our sun will become a red giant and then shrink into a white dwarf, where it will spend the rest of its life.

Source: A Jovian analogue orbiting a white dwarf star

Via Keck Observatory


Arline J. Mercier