"Though TOI 1231 b is eight times closer to its star than the Earth is to the Sun, its temperature is similar to that of Earth, thanks to its cooler and less bright host star," said study co-author Diana Dragomir, an assistant professor in the University of New Mexico's department of physics and astronomy, in a statement.
"However, the planet itself is actually larger than earth and a little bit smaller than Neptune - we could call it a sub-Neptune."
Nasa said that the newly-discovered exoplanet, TOI-1231 b, is more than three and a half times as big as Earth, calling it “oddly reminiscent” of Neptune.
What Is an Exoplanet?
Astronomers have discovered an exoplanet located 90 light-years away from Earth with a potentially rich atmosphere that may contain water clouds. Nasa said that the newly discovered exoplanet is more than three-and-a-half times as big as Earth, calling it “oddly reminiscent” of Neptune.
The exoplanet named TOI-1231 b orbits a red-dwarf star that, according to Nasa, is “smaller but longer-lived” than the Sun.
The exoplanet revolves once around the star in a year that is 24 days long. Despite the proximity to the star, TOI-1231 b is relatively cool because the red-dwarf star is also on the cooler side. Nasa said that the exoplanet could offer scientists the chance to capture a “bar-code” type reading of the atmosphere of a temperate planet orbiting another star.
“This will allow comparisons with similar worlds elsewhere in the galaxy, bringing potentially deep insights into the composition and formation of exoplanets and planetary systems, including our own,” Nasa’s exoplanet exploration program said in a statement.
Why This Exoplanet Might Have Clouds?
Researchers were able to determine the planet's radius and mass, which helped them calculate its density and infer its composition.
The exoplanet has a low density, which suggests it's a gaseous planet rather than a rocky one like Earth, but scientists don't yet know for certain the composition of the planet or its atmosphere.
Jennifer Burt, a postdoctoral fellow at NASA's Jet Propulsion Laboratory in Pasadena, California, said, "TOI-1231 b is pretty similar in size and density to Neptune, so we think it has a similarly large, gaseous atmosphere."
Also, "TOI1231b could have a large hydrogen or hydrogen-helium atmosphere, or a denser water vapour atmosphere."
"Each of these would point to a different origin, allowing astronomers to understand whether and how planets form differently around M dwarfs when compared to the planets around our Sun, for example."
The researchers believe TOI-1231 b has an average temperature of 60 degrees Celsius, which makes it one of the coolest of the small exoplanets available for future study of its atmosphere.
The cooler the exoplanet, the more likely it is to have clouds in its atmosphere.
The similarly small exoplanet K2-18 b, discovered in 2015, was recently observed in more detail, and researchers found evidence of water in its atmosphere.
Also Ms. Burt said in a statement, "TOI-1231 b is one of the only other planets we know of in a similar size and temperature range, so future observations of this new planet will let us determine just how common (or rare) it is for water clouds to form around these temperate worlds."
Search Operation for Exoplanet
Burt, Dragomir and their colleagues discovered the planet using data from NASA's Transiting Exoplanet Survey Satellite, or TESS. The planet-hunting satellite, launched in 2018, observes different areas of the sky for 28 days at a time.
So far, TESS has helped scientists find large and small exoplanets orbiting stars like our sun as well as the smaller M dwarf stars. These diminutive stars are common in the Milky Way galaxy.
These diminutive stars are common in the Milky Way galaxy. So When a planet crosses in front of its star during orbit, it blocks a certain amount of light. This is called a transit, and it's one way astronomers search for exoplanets using missions like TESS.
Given that M dwarf stars are smaller, the amount of light blocked by a planet orbiting them is larger, which makes the transit more detectable.
Scientists look for at least two transits before determining if they have found an exoplanet candidate. Follow-up observations were made using the Planet Finder Spectrograph on the Magellan Clay telescope at Las Campanas Observatory in Chile.
Ms. Burt said, "One of the most intriguing results of the last two decades of exoplanet science is that, thus far, none of the new planetary systems we've discovered look anything like our own solar system."
%20(1).jpg)
0 Comments