For the first time, astronomers have identified a planet headed for a catastrophic collision with its aging sun, potentially offering a glimpse of how Earth could one day end.
In a new study published Monday, a team of mostly American researchers said they hope the doomed exoplanet Kepler-1658b can help shed light on how worlds die as their stars age.
Kepler-1658b, which is 2600 light-years from Earth, is known as a “hot Jupiter” planet.
Although similar in size to Jupiter, the planet orbits its host star one-eighth the distance between our sun and Mercury, making it much hotter than the gas giant in our own solar system.
Kepler-1658b’s orbit around its host star lasts less than three days — and it’s getting shorter by about 131 milliseconds per year, according to the study published in The Astrophysical Journal Letters.
“If it continues to orbit toward its star at the observed speed, the planet will collide with its star in less than three million years,” said Shreyas Vissapragada, a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics and the study’s lead author. .
“This is the first time we have observed direct evidence of a planet spiraling towards its evolved star,” he told AFP.
An evolved star has entered the “subgiant” stage of a star’s life cycle, when it begins to expand and brighten.
Kepler-1658b’s orbit is shortened by the tides, in a similar process to how Earth’s oceans rise and fall each day.
This gravitational push and pull can work both ways — the moon, for example, is moving very slowly away from the earth.
– Earth’s ‘ultimate adios’? –
So could Earth be headed for a similar doom?
“Death-by-star is a fate thought to await many worlds and could be Earth’s ultimate adios billions of years from now as our sun ages,” the Center for Astrophysics said in a statement.
Vissapragada said that “in about five billion years the sun will evolve into a red giant star”.
While the tide-driven processes seen on Kepler-1658b “will cause the decay of Earth’s orbit toward the sun,” that effect could be offset by the sun losing mass, he said.
“Earth’s ultimate fate is somewhat unclear,” he added.
Kepler-1658b was the first exoplanet ever observed by the Kepler space telescope, which launched in 2009. However, it took nearly a decade for the planet’s existence to be confirmed in 2019, according to the Center for Astrophysics.
For more than 13 years, astronomers were able to observe the slow but steady change in the planet’s orbit as it passed the face of its parent star.
One “big surprise” was that the planet itself is quite bright, Vissapragada said.
It was previously thought that this was because it is a particularly reflective planet, he said.
But now the researchers believe the planet itself is much hotter than expected, possibly due to the same forces propelling it toward its star.
(Except for the headline, this story has not been edited by NDTV staff and is being published from a syndicated feed.)
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