Scientists unveil catalog of strange new worlds beyond our solar system

Artist conception of 126 planets in the latest TESS-Keck Survey catalog is based on data including planet radius, mass, density, and temperature. Question marks represent planets requiring more data for full characterization. Credit: W. M. Keck Observatory/Adam Makarenko.

An international team of scientists has discovered 126 new planets outside our solar system.

These exotic worlds have been added to a special NASA catalog that provides detailed measurements, allowing us to compare them with the planets in our own solar system.

This catalog includes a variety of planet types, from those with extreme environments to some that might even support life.

The planets were studied by a large team of scientists using NASA’s Transiting Exoplanet Survey Satellite (TESS) and the W.M. Keck Observatory in Hawai’i.

Their findings are published in The Astrophysical Journal Supplement.

“Not many of the previously known exoplanets have both their mass and radius measured. These measurements tell us what the planets could be made of and how they formed,” said Stephen Kane, an astrophysicist at UC Riverside and the principal investigator of the TESS-Keck Survey.

With this new information, scientists can start to answer questions about how our solar system fits into the larger picture of planetary systems.

The research team spent three years developing the catalog, analyzing over 13,000 radial velocity (RV) measurements to calculate the masses of 120 confirmed planets and six candidate planets across the northern sky.

Though the planets themselves aren’t visible, their presence is detected through their effects on their host stars. As these planets orbit, they tug on their stars, causing them to “wobble.” When a star moves toward a telescope, its light turns slightly bluer; when it moves away, the light shifts slightly redder, much like how a siren changes pitch as it moves closer or farther away.

“These RV measurements help astronomers detect and learn about these exoplanetary systems. When we see a star wobbling regularly, we can infer the presence of an orbiting planet and measure its mass,” said Ian Crossfield, a University of Kansas astrophysicist and co-author of the catalog.

Several planets in the TESS-Keck Survey stand out for their unique properties. For example, UCR graduate student Michelle Hill discovered two new planets orbiting a star like our sun. One is a “sub-Saturn” planet with a mass and radius between those of Neptune and Saturn, taking only 26 days to orbit its star.

Its neighbor, a planet with a mass close to that of Saturn, takes 227 days to complete its orbit.

Another interesting find by UCR graduate student Daria Pidhorodetska is a planet about half the size of Neptune that takes just 19 days to orbit its star. These small but significant discoveries remind us of the incredible diversity of the universe.

The catalog also includes planets with extremely short orbits around stars unlike our sun. For instance, TOI-1798 c is so close to its orange dwarf star that it completes an orbit in less than 12 hours, making it ultra-hot and likely devoid of an atmosphere.

This new catalog is a major contribution to NASA’s TESS mission and helps scientists answer the question of whether other planets can host life as we know it. “Are we unusual? The jury is still out on that one, but our new catalog represents a major step toward answering that question,” Kane said.