Heat stroke coming for Kepler-1658b… Astronomers have seen a distant planet dangerously close to its aging star for the first time, according to a study published Monday that offers possible insight into how Earth could end.
Located 2,600 light-years from Earth, Kepler-1658b is an exoplanet – that is, a planet outside the solar system – about the same size as Jupiter. But unlike this gas giant far from the Sun, Kepler-1658b orbits its star only one-eighth the distance that separates our star from Mercury, its closest planet.
Collision in less than three million years
This “hot Jupiter” orbits its star in less than three days, and this period of revolution shortens by about 131 milliseconds per year, describes a study published in The Astrophysical Journal Letters.
“At this rate, the planet will collide with its star in less than three million years”, analyzes Shreyas Vissapragada, from the Harvard Center for Astrophysics – Smithsonian, lead author of the study.
“This is the first time we have observed direct evidence of a planet with a spiral orbit around its aging star”, explains the astrophysicist to AFP. The star in question is at an advanced stage in its cycle when it begins to swell and become brighter and brighter.
Kepler-1658b’s orbit is inexorably falling under the influence of the star’s gravitational pull, similar to that exerted by the Moon at various points on Earth. This effect called tidal force can attract two bodies as well as it can move them away from each other – the Moon, for example, moves very slowly away from Earth in a spiral orbit.
Same inevitable end for Earth?
Will our planet experience the same dissolution process? “A stellar-induced death of a planet is a fate that awaits many worlds and may be Earth’s ultimate farewell billions of years from now as our Sun evolves,” writes the Astrophysics Center in a press release.
In about 5 billion years, the Sun will become a “red giant” that will grow larger and larger, along the lines of the host star of Kepler-1658b.
Like the exoplanet, Earth could move inexorably closer to the Sun under the influence of tidal forces. But this effect can also be offset by the loss of mass from the Sun, specifies Shreyas Vissapragadan, who emphasizes that “Earth’s ultimate fate remains unclear”.
Kepler-1658b has been exciting for thirteen years
Kepler-1658b was the first exoplanet observed with the Kepler space telescope, in 2009. For 13 years, scientists had observed the slow but steady change in the planet’s orbit as it passed in front of its host star.
Finding it surprisingly bright compared to other exoplanets, they have long assumed that it reflects starlight particularly well. They now believe that Kepler-1658b is even hotter than expected due to the attraction exerted by the star.