New exoplanet catalog unveils 126 exotic worlds

• A new catalog contains 126 newly discovered exoplanets. The NASA publication contains 120 confirmed exoplanets and six candidates awaiting confirmation.
• The planets range from extreme with searing temperatures and short orbits, to ones that may be potentially habitable.
• The discoveries will help astronomers better understand planetary formation and compare the new planets to ones in our own solar system.

New catalog showcases 126 exoplanets

Only a few decades ago, astronomers didn’t know if there were any planets beyond our solar system. Now, thousands of these worlds – called exoplanets – have been discovered. An international team of researchers has published a new NASA exoplanet catalog featuring 126 newly discovered exotic exoplanets. The researchers said on May 23, 2024, that the catalog includes a wide variety of planets. Some are extreme and uninhabitable while others may potentially be able to support life. The detailed measurements will allow astronomers to compare them with the planets in our own solar system.

The astronomers used both NASA’s Transiting Exoplanet Survey Satellite (TESS) and the W.M. Keck Observatory in Hawaii. They published their peer-reviewed results in The Astrophysical Journal on May 23, 2024.

126 newly discovered worlds in exoplanet catalog

The catalog contains 120 newly confirmed planets and six candidates. The catalog is unique in that it contains measurements for both the mass and radius of the included exoplanets. Stephen Kane at University of California, Riverside, is an astrophysicist and principal investigator of the TESS-Keck Survey. He stated:

Relatively few of the previously known exoplanets have a measurement of both the mass and the radius. The combination of these measurements tell us what the planets could be made of and how they formed. With this information, we can begin to answer questions about where our solar system fits in to the grand tapestry of other planetary systems.

Strange worlds

As with other exoplanet discoveries over the past few decades, the types of planets in the new exoplanet catalog vary widely. Some are extreme and unlikely to support any life, while others are potentially habitable. The findings further confirm that planets can form and evolve in many diverse ways. Some are similar to planets in our own solar system, while others are unlike any in our sun’s family of planets.

One example is TOI-1386 b. It’s what astronomers call a sub-Saturn, and it orbits a sun-like star. It has a radius and mass between that of Saturn and Neptune. These planets have been difficult to find so far. Co-author Michelle Hill, a graduate student at University of California, Riverside, said:

There is ongoing debate about whether sub-Saturn planets are truly rare, or if we are just bad at finding planets like these. So, this planet, TOI-1386 b, is an important addition to this demographic of planets.

Like many other discovered exoplanets, TOI-1386 b orbits very close to its star. In fact, it completes an orbit in only 26 days. Another planet in the same system takes 227 days to complete one orbit. This one is almost the same mass as Saturn. Hill and her colleagues published their own paper about these two worlds on March 13, 2024, in The Astronomical Journal.

Planets smaller than Neptune the most common

Another planet, TOI-1437 b, also orbits a sun-like star. It’s about half the size of Neptune and orbits once every 19 days. Lead author of that paper, Daria Pidhorodetska, is also a graduate student at University of California, Riverside. As Pidhorodetska noted, such planets are common, even though there are none in our own solar system:

Planets smaller than Neptune but larger than Earth are the most prevalent worlds in our galaxy, yet they are absent from our own solar system. Each time a new one is discovered, we are reminded of how diverse our universe is, and that our existence in the cosmos may be more unique than we can understand.

More planets orbiting sun-like stars

Most of the stars in our galaxy are red dwarfs. And most of the exoplanets found so far are around such stars. So finding new ones orbiting sun-like stars is exciting and scientifically important. It also makes it easier to compare those planets with planets in our solar system. Kane added:

Then we can do apples-to-apples comparisons. That’s the exciting part of the papers produced by Michelle and Daria, because they allow for this.

A planet with a 12-hour year

There are some even more extreme planets in the exoplanet catalog. TOI-1798 c, a super-Earth, orbits its orange dwarf star in only 12 hours. Being so close to their stars, the planets are extremely hot and irradiated. Alex Polanski, lead author of the catalog paper at the University of Kansas, said:

TOI-1798 c orbits its star so quickly that one year on this planet lasts less than half a day on Earth. Because of their proximity to their host stars, planets like this one are also ultra hot, receiving more than 3,000 times the radiation that Earth receives from the sun.

Rocky planets orbiting so close to red dwarfs are in danger of having their atmospheres stripped away by the radiation. The same is true for TOI-1798 c, as Polanski noted:

Existing in this extreme environment means that this planet has likely lost any atmosphere that it initially formed.

Is our solar system unusual?

We’ve come a long way from not knowing if there even are any other planets out there to finding thousands of worlds. Some of them are unlike any ever seen before. In such a huge universe, it seems that planets of almost any conceivable type are possible. Now, astronomers can start to compare these planetary systems with our own, and find out just how unique – or not – our solar system actually is. Kane said:

Are we unusual? The jury is still out on that one, but our new mass catalog represents a major step toward answering that question.

Bottom line: A new NASA exoplanet catalog unveils 126 newly discovered worlds ranging from scorched wastelands to ones that may be able to support life.

Source: The TESS-Keck Survey. XX. 15 New TESS Planets and a Uniform RV Analysis of All Survey Targets

Via UC Riverside

Read more: Exoplanets are worlds orbiting other stars

Read more: Rocky exoplanets can form in the most extreme environments