2,200 exoplanet candidates discovered in 2 years: TESS has been busy

By Georgina Torbet March 27, 2021

Illustration of TESS — Illustration of TESS NASA

NASA’s Transiting Exoplanet Survey Satellite, or TESS, the planet-hunting satellite, is celebrating an impressive achievement: A total of more than 2,200 exoplanet candidates discovered in its first two years of operations.

Launched in 2018, the satellite searches for planets outside of our solar system using the transit method. This means that it looks for changes in the brightness levels of distant stars. When a planet passes between a star and Earth, the star’s brightness dips by a small amount. TESS looks out for these dips and uses them to infer the presence of a planet and to estimate its characteristics like size and mass.

All of the candidate planets that it found evidence for have now been cataloged in a new paper by researchers lead by Natalia Guerrero, a researcher at the Massachusetts Institute of Technology.

“The exciting thing is to look at the map of TESS exoplanets as a kind of to-do list — with 2,000 things on it,” Guerrero said in a statement.

TESS’s candidate discoveries including an Earth-sized planet in the habitable zone called TOI-700 d, which is around 100 light-years away and which is close enough to its small, cool red dwarf star that it could potentially have liquid water on its surface. It also discovered a system called TOI 125, a star similar to our sun which hosts at least three planets smaller than Neptune and possibly two more small planets as well. And there’s the extreme short-orbit planet LHS 3844 b, which orbits so close to its star that a year there lasts just 11 days and has a surface temperature of nearly 1,000 degrees Fahrenheit.

Since completing its original two-year mission, TESS is now on an extended mission to discover more exoplanets and to uncover more details about those it has already found evidence for. It takes time and patience to confirm the existence of a candidate planet, and so far around 120 of the candidates discovered by TESS have been confirmed.

“Now the community’s role is to connect the dots,” Guerrero said. “It’s really cool because the field is so young, there’s still a lot of room for discovery: those ‘Aha’ moments.”

Topics

Georgina Torbet

Space Writer

Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…

Space

Astronomers discover three exoplanets in final data from Kepler Space Telescope

An artist's concept of the Kepler spacecraft.

The Kepler Space Telescope was retired in 2018 after a nine-year mission that saw it discover an incredible 2,600 confirmed exoplanets, kicking off the modern era of exoplanet research. But now there are three more exoplanets to add to the mission's total, even after the telescope has been dark for the last five years. Astronomers were recently able to use data from the very last observations of Kepler to discover three more planets.

Two of the three exoplanets have been confirmed -- K2-416 b and K2-417 b -- with a third planet, EPIC 246251988 b, remaining an exoplanet candidate. (To be upgraded from exoplanet candidate to confirmed exoplanet, an initial observation has to be verified through observations by two other telescopes.) The planets range from 2.6 times the size of Earth to 4 times the size of Earth, making them small in comparison to most discovered exoplanets.

Space

Astronomers discover Earth-sized exoplanet covered in volcanoes

Exoplanet LP 791-18 d, illustrated in this artist’s concept, is an Earth-size world about 90 light-years away. A more massive planet in the system, shown as a small blue dot on the right, exerts a gravitational tug that may result in internal heating and volcanic eruptions, like on Jupiter’s moon Io.

Astronomers have discovered an Earth-sized planet that is highly volcanically active -- an unusual finding that means it could possibly support life. The newly discovered planet, LP 791-18d, is thought to be covered in volcanoes and could be as active as Jupiter's moon Io, which is the most volcanically active body in our solar system.

Exoplanet LP 791-18 d, shown in this artist’s concept, is an Earth-size world about 90 light-years away. A more massive planet in the system, shown as a small blue dot on the right, exerts a gravitational tug on the exoplanet that may result in internal heating and volcanic eruptions, like on Jupiter’s moon Io. NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)

Space

Previously unknown exoplanet discovered using machine learning

exoplanet discovered machine learning image png

When it comes to discovering new astronomical bodies, sometimes humans are irreplaceable thanks to their skills in pattern detection. But in other cases, computers can spot things that aren't visible to humans -- including a recent instance where an exoplanet was discovered using machine learning.

The exoplanet was discovered by University of Georgia researchers within a protoplanetary disk called HD 142666. A protoplanetary disk is a rotating disk of gas that swirls around young stars, and from which planets are formed. Planets are formed within these disks as matter clumps together until it eventually has enough gravity to pull more material in. The researchers looked at a previous set of observations of a whole set of protoplanetary disks, and used a machine learning model to search for exoplanets that might have been missed the first time around. They identified one disk where a planet was likely to be, based on the unusual way that gas moved around within the disk.