Skip to main content

Teenage ‘lava world’ is the youngest exoplanet of its type discovered so far

TESS Finds Related Stars Have Young Exoplanets

Exoplanets come in many different types and sizes, and to understand how planets form and develop, it’s helpful to see them at a variety of different points throughout their life cycle. NASA’s exoplanet-hunting satellite TESS has recently discovered four “teenage” exoplanets, including one dramatic lava world that orbits ultra-close to its star.

TESS investigated two young stars that are close to each other and thought to be related, TOI 2076 and TOI 1807. It found four exoplanets in orbit around them that are in a rarely-spotted middle phase between recent birth and maturity.

“The planets in both systems are in a transitional, or teenage, phase of their life cycle,” said Christina Hedges, an astronomer at the Bay Area Environmental Research Institute in Moffett Field and 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 orbit TOI 2076, each of which is called a mini-Neptune, as they are between Earth and Neptune in size.

But the really dramatic planet is the one seen orbiting TOI 1807. The planet, TOI 1807 b, is so close to its star that a year there lasts just 13 hours. This planet is the youngest version of such a planet, called an ultra-short period planet, yet discovered. If the planet is mostly rock and doesn’t have a thick atmosphere, researchers predict that it could be covered in lakes or even oceans of lava.

Potential lava world TOI 1807 b.
Short-period planets, or those with orbits shorter than one day, are rare. Potential lava world TOI 1807 b, illustrated here, is the youngest example yet discovered. NASA’s Goddard Space Flight Center/Chris Smith (KBRwyle)

This planet is also bombarded with UV radiation because its star is so young and active. It is estimated that the planet is hit with 22,000 times the amount of UV radiation from its star than Earth gets from the sun. And the other star is similarly active as well.

“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.”

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble and Spitzer spot two far-off watery worlds
In this illustration super-Earth Kepler-138 d is in the foreground. To the left, the planet Kepler-138 c, and in the background the planet Kepler 138 b, seen in silhouette transiting its central star. Kepler 138 is a red dwarf star located 218 light-years away. The low density of Kepler-138 c and Kepler-138 d — which are nearly identical in size — means that they must be composed largely of water.

While we have discovered over 5,000 exoplanets to date, most of the information we have about these planets is fairly basic. Researchers typically know about a planet's mass or radius and its distance from its host star, but little more than that, making it hard to predict what these worlds are actually like. However, new tools and techniques are allowing researchers to learn more about details like a planet's density, allowing a better understanding of what these places are like.

Recently, researchers using data from the Hubble Space Telescope and Spitzer Space Telescope have identified two planets that seem to be water worlds, with oceans that are 500 times deeper than the oceans on Earth.

Read more
How the ‘hell planet’ covered in lava oceans got so close to its star
An artist’s impression of the planet Janssen (orange circle), which orbits its star so closely that its entire surface is a lava ocean that reaches temperatures of around 2,000 degrees Celsius.

Of the over 5,000 known planets outside our solar system, one of the most dramatic is 55 Cancri e. Affectionately known as the "hell planet," it orbits so close to its star that it reaches temperatures of 3,600 degrees Fahrenheit and its surface is thought to be to covered in an ocean of lava. Located 40 light-years away, the planet has been a source of fascination for its extreme conditions, and recently researchers shared a new theory for how it got so hot.

The planet orbits its star, 55 Cancri A, at a distance of 1.5 million miles which means a year there lasts less than a day here on Earth. “While the Earth completes one orbit around our sun in 365 days, the planet studied here orbits once every 17.5 hours, hugging its host star, 55 Cnc,” said study author Debra Fischer of Yale University in a statement.

Read more
Super-sensitive exoplanet-hunting instrument captures its first light data
James Chong, infrastructure technician at Keck Observatory, assisting with the delicate lift of the Zerodur optics bench into the observatory basement where the instrument resides.

Astronomers will soon have a new tool for hunting exoplanets, as the W. M. Keck Observatory's Keck Planet Finder (KPF) instrument recently took its first observations. KPF's "first light" observations captured data from Jupiter, demonstrating how the instrument will be able to detect planets beyond our solar system in the future.

Located at Maunakea in Hawaiʻi, the new instrument detects exoplanets using the radial velocity method. This works by observing a star and looking for a slight wobble, caused by the gravity of planets orbiting around it. This wobble changes the light coming from the star just slightly, in a way that can be used to work out the properties of the planet. The instrument measures spectra, or the wavelengths of light coming from a star, with more massive planets making bigger wobbles.

Read more