For the first time, astronomers say they have seen an exoplanet spiraling toward its older star, which will eventually be destroyed in a cosmic collision.
Interestingly, this distant planet already had a reputation as the first exoplanet candidate detected by NASA’s Kepler Space Telescope. Kepler-1658b was first identified in Kepler data in 2009, but it took a full decade for its existence to be formally confirmed by additional analysis. Now it turns out that the massive planet, which is almost six Jupiter-sized, may have much less time left than originally thought.
Shreyas Vissapragada of the Harvard and Smithsonian Center for Astrophysics, lead author of a new study on the finding, published Monday in The Astrophysical Journal Letters, said: “We have previously detected evidence that exoplanets spiral toward their stars, but no such planet is found around an evolved star. “The theory predicts that evolved stars are very effective at drawing energy from the orbits of their planets, and we can now test these theories with observations.”
It’s no coincidence that the first exoplanet detected by Kepler was a gas giant planet orbiting close to its star. These planets, also called “Hot Jupiters”, are relatively easy to detect because they are very large and close to their parent star.
Kepler-1658b orbits Kepler 1658 closer to the star than Mercury does to our sun, completing a full orbit around the star every 3.85 days. But researchers now say its orbital period is decreasing by 131 milliseconds each year, suggesting that the planet is slowly approaching its star and its own death.
This slow spiral is caused by tidal or gravitational interactions between the two bodies, the researchers say. Kepler-1658 appears to have entered the final stages of its life, when it begins to expand outward, which is expected to enter our Sun a few billion years later.
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