https://www.space.com/exoplanet-catalog-126-worlds-solar-system
Massive new NASA exoplanet catalog unveils 126 extreme and exotic worlds
May 25, 2024
A new catalog of 126 worlds beyond the solar system contains a cornucopia of newly discovered planets — some have extreme and exotic natures, but others could potentially support life as we know it.
The catalog's mix of planets is further evidence of the wide and wild variety of worlds beyond our cosmic backyard; it even shows that our solar system is perhaps a little boring.
Yet, despite these planets being so different than Earth and its neighbors, maybe they can still help us better understand why our planetary system looks the way it does, thus uncovering our place in the wider cosmos.
The catalog of extrasolar planets, or "exoplanets," was created using data from NASA's Transiting Exoplanet Survey Satellite (TESS) in collaboration with the W.M. Keck Observatory in Hawaii.
"With this information, we can begin to answer questions about where our solar system fits into the grand tapestry of other planetary systems," Stephen Kane, TESS-Keck Survey Principal Investigator and an astrophysicist at the University of California, Riverside, said in a statement.
The new TESS-Keck Survey of 126 exoplanets really stands apart from previous exoplanet surveys because it contains complex data about the majority of planets included.
"Relatively few of the previously known exoplanets have a measurement of both the mass and the radius," Kane added. "The combination of these measurements tells us what the planets could be made of and how they formed."
The catalog was built over the course of three years as the team used 13,000 measurements of tiny "wobbles" that planets cause as they orbit their stars and exert a tiny gravitational tug on them.
This tug causes a star to move slightly away, then slightly toward, Earth.
When stars are pulled slightly away, this stretches the wavelengths of light they emit, moving them toward the "red end" of the electromagnetic spectrum.
When stars move toward Earth, the wavelength of the light they omit is slightly compressed, making it "bluer."
The exploitation of redshift and blueshift in this way by astronomers is called the "radial velocity method." Because the strength of the gravitational pull a planet exerts on a star is proportional to its mass, it is a good way of determining mass.
Thus, the radial velocity method allowed Kane and team to determine the mass of 120 confirmed exoplanets and six exoplanet candidates.
"These radial velocity measurements let astronomers detect and learn the properties of these exoplanetary systems," Ian Crossfield, University of Kansas astrophysicist and catalog co-author, said.
"When we see a star wobbling regularly back and forth, we can infer the presence of an orbiting planet and measure the planet’s mass."
Excitingly, some of the 126 exoplanets in the TESS-Keck Survey could deepen astronomers' understanding of how an array of diverse planets form and evolve.
Two of the new planets featured in the TESS-Keck Survey orbit a sun-like star called TOI-1386, which is located around 479 light-years away.
One of these exoplanets has a mass and width that put it somewhere between the solar system gas giant Saturn and the smaller, less massive ice giant Neptune. That makes this planet, designated TOI-1386 b, a "sub-Saturn" planet and a fascinating target for planetary scientists.
"There is an ongoing debate about whether sub-Saturn planets are truly rare, or if we are just bad at finding planets like these," discoverer and UCR graduate student Michelle Hill said in the statement.
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