Exoplanets are found across the universe in different types and sizes, and to determine how they formed and developed, it’s important to observe them at different times throughout their life cycle. NASA’s TESS has recently found four young exoplanets, including one lava world that orbits very close to its star.
TESS observed two young stars that are close to each other – TOI 2076 and TOI 1807. It discovered four exoplanets in orbit around them that are in a middle phase between birth and maturity.
Four mini-Neptune discovered
“The planets in both systems are in a transitional, or teenage, phase of their life cycle,” said Christina Hedges, an astronomer at NASA’s Ames Research Center in Silicon Valley. “They’re not newborns, but they’re also not settled down. Learning more about planets in this teen stage will ultimately help us understand older planets in other systems.”
Three of the exoplanets revolve around TOI 2076, each of them is called mini-Neptune, as their size falls between Earth and Neptune. But the one planet that caught everyone’s attention was the one orbiting TOI 1807. The planet, TOI 1807 b, orbits so close to the star that a year on it lasts only 13 hours.
This planet is the youngest exoplanet ever discovered, called an ultra-short period planet. If the planet is mostly rock and doesn’t feature a thick atmosphere, scientists believe that it could be covered in lakes or even oceans of lava.
Highly exposed to UV radiation
This planet is also exposed to high levels of UV radiation because its star is young and active. Astronomers suggest that the planet is bombarded with 22,000 times the amount of UV radiation from its star that our planet gets from the sun.
“The stars produce perhaps 10 times more UV light than they will when they reach the sun’s age,” said co-author George Zhou, an astrophysicist at the University of Southern Queensland in Australia. “Since the sun may have been equally as active at one time, these two systems could provide us with a window into the early conditions of the solar system.”
