White dwarfs are stars the size of our Sun that has reached the end of their lives. When the hydrogen in their core is depleted, they swell up, losing their outer layers one by one until just the star core remains. The nearest planets to such stars were supposed to be disrupted and destroyed by this process, but researchers have discovered one that appears to have remained relatively intact. In the journal Nature, an international team of astronomers reports on this survivor. The planet is orbited by a white dwarf with a mass of around 53% that of our Sun. The planet has a mass of 1.4 times that of Jupiter and orbits its star at a distance of 420 million kilometers (260 million miles). That is around the distance between the Sun and Ceres, the biggest object in the Asteroid Belt, in the solar system.
It has always appeared feasible that planetary systems could survive the cataclysmic phases of star evolution in white dwarfs. Planets have discovered surviving destructive events such as supernovae. However, astronomers have only discovered evidence of destroyed planets or asteroid belts thus far. They also expected to find planets further out, rather than (relatively) close by.
Given that 97 percent of the Milky Way’s stars are projected to follow this route (though some will not for billions of years), it has crucial to know what will happen to their planetary systems. According to estimates, 50% of all white dwarfs have companions the size of Jupiter. This is the first of them.
A technique is known as microlensing is used to discover the planet. The planet’s gravity was strong enough to distort the light of its host star, similar to how a glass lens would distort a candle’s picture and brightness. As the planet orbits the white dwarf, the light from the white dwarf shifts, allowing scientists to determine the planet’s presence.
Based on an initial finding in 2010 and follow-up observations in 2015, 2016, and 2018, the team estimated the parameters of this gas giant planet. They calculate the current estimation of this system using that data, a gas giant planet orbiting the point when star evolution comes to a halt. This planetary system is located 6,500 light-years from the Milky Way’s core. The planetary system and others that will undoubtedly discover are a peek into the Solar System’s future. Mercury and Venus anticipated destroying when the Sun turns into a red giant, and Earth and Mars may have a slim chance of surviving. Even if the Sun transforms into a white dwarf, Jupiter will still be there.
