Despite the fact that thousands of planets have been found orbiting other stars, not much is known about them. There are 126 strange, recently found worlds included in a NASA catalog with precise measurements that let us compare them to our own solar system.
The collection describes a diverse range of extrasolar planet types, from uncommon worlds with harsh environments to those that might harbor life.
A sizable, multinational scientific team worked with the W.M. Keck Observatory on Maunakea, Hawaii, and NASA’s Transiting Exoplanet Survey Satellite (TESS) to investigate the planets. Today’s edition of The Astrophysical Journal Supplement Series contains a description of them.
“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,” according to Stephen Kane, principle investigator of the TESS-Keck Survey and astronomer at UC Riverside.
“With this information, we can begin to answer questions about where our solar system fits in to the grand tapestry of other planetary systems,” Kane stated.
The catalog took three years to develop for the research team. Over 13,000 radial velocity (RV) measurements were processed in order to determine the masses of 120 verified planets and six candidate planets that are dispersed across the northern sky.
Despite not being seen, the planets do have an effect that is. The planets pull on their host stars as they revolve, making them “wobble.” A star’s visible light shifts somewhat bluer when it moves toward a telescope and redder when it goes away from us.
This behavior is similar to that of sound. The Doppler effect causes the siren of a fire vehicle to sound higher when it approaches and lower when it moves farther away.
Astronomers can identify and understand the characteristics of these exoplanetary systems thanks to these RV data. According to Ian Crossfield, an astrophysicist and co-author of the catalog from the University of Kansas, “we can determine the mass of an orbiting planet and deduce its presence when we observe a star oscillating regularly back and forth.”
Astronomers can gain a deeper knowledge of the various ways planets develop and evolve by examining a few planets that stand out as touchstones in the TESS-Keck Survey.
Two new planets have been found around a star similar to our sun, according to a related survey report written by Michelle Hill, a PhD student at UCR, and published in The Astronomical Journal. The first planet is classified as a “sub-Saturn” since its mass and radius fall between those of Saturn and Neptune.
“There is ongoing debate about whether sub-Saturn planets are truly rare, or if we are just bad at finding planets like these,” Hill stated. “So, this planet, TOI-1386 b, is an important addition to this demographic of planets.”
In about 26 days, TOI-1386 b completes its orbit around its star. In the meantime, it takes 227 days for its neighbor, a planet with a mass similar to Saturn’s, to orbit the same star.
Another survey study describes a planet roughly half the size of Neptune that orbits its star, which is similar to our sun, in just 19 days. It was written by UCR graduate student Daria Pidhorodetska and is accessible on the arXiv preprint service.
“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,” Pidhorodetska stated.
Numerous stars do not resemble our sun at all. Scientists need to locate stars with comparable mass, age, and size in order to draw appropriate parallels between our planet and other worlds. “Then we can do apples-to-apples comparisons,” Kane stated. “That’s the exciting part of the papers produced by Michelle and Daria, because they allow for this.”
The catalog also includes details on planets that orbit stars that are even more extreme and ultra-short than our sun. One orbits its orange dwarf star in less than 12 hours since it is so near to it.
“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,” stated Alex Polanski, a PhD student in physics and astronomy at the University of Kansas and the primary author of the catalog paper.
“Existing in this extreme environment means that this planet has likely lost any atmosphere that it initially formed,” Polanski stated.