Astronomers have seen a planet only 90 light-years away from Earth with a surprising atmosphere – and the possibility of clouds containing water.
TOI-1231 b is a, which means it is located outside our solar system. It was discovered by a team of scientists from NASA’s Jet Propulsion Laboratory and the University of New Mexico who will publish their findings in an upcoming issue of The Astronomical Journal.
TOI-1231 b was detected using data from the Transiting Exoplanet Survey Satellite (TESS) and confirmed using the Planet Finder Spectrograph (PFS) on the Magellan Clay Telescope in Chile. The PFS revealed details about the mass and orbits of the exoplanet by observing its gravitational influence on the host star.
In just 24 Earth days, TOI-1
NLTT 24399 is smaller, lighter and weaker than our sun, which actually made it possible to detectrelatively easy.
“Imagine an Earth-like planet passing in front of a star the size of the sun, it will block a little bit of light; but if it passes in front of a star that is much smaller, the proportion of light that is blocked out will be bigger, “said researchers. “In a way, this creates a larger shadow on the star’s surface, making planets around M dwarfs easier to detect and easier to study.”
The perfect candidate for observation
Astronomers determined that TOI-1231 b “strangely resembles” Neptune, both in size and density, leading them to believe that it is also gaseous – not rocky like Earth. However, its temperature is more similar to the temperature of our home planet.
“Although TOI 1231 b is eight times closer to its star than Earth is to the sun, its temperature is similar to Earth, thanks to its cooler and less bright host star,” said study author Diana Dragomir. “However, the planet itself is actually larger than Earth and slightly smaller than Neptune – we could call it a sub-Neptune.”
With a temperature of approx. 140 degrees Fahrenheit, the TOI-1231 b is one of the coolest, small onesfor future atmospheric exploration ever discovered.
“Compared to most transit planets discovered so far, which often havein the many hundreds or thousands of degrees, the TOI-1231 b is positively frigid, “said lead author Jennifer Burt.
Previous studies suggest that planets with such a low temperature may have clouds in their atmosphere. Recently discovered, K2-18 showed signs of water clouds – shocking scientists.
“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 how common (or rare) it is to form. water clouds around these temperate worlds, “Burt said.
And that is not the only peculiarity of the planetary system. It moves away from Earth at such a high speed that scientists can easily detect hydrogen atoms escaping from its atmosphere – like a tail behind the planet.
“The low density of TOI-1231 b indicates that it is surrounded by a significant atmosphere rather than being a rocky planet. But the composition and extent of this atmosphere is unknown!” said Dragomir. “TOI-1231 b could have a large hydrogen or hydrogen helium atmosphere or a denser water vapor atmosphere. Each of these would point to a different origin so astronomers could understand if and how planets form differently around M dwarfs compared to planets around our sun, e.g. “
A new era of exoplanet studies
NASA scientists say these types of discoveries mark a new era in the study of exoplanets. They move from simply discovering these unusual planets to actually observing specific worlds and understanding their atmosphere.
Using a technique called transmission spectroscopy, scientists hope to capture starlight in the planet’s atmosphere. Molecules in the atmosphere absorb this light, leaving dark lines “that can be read as a bar code” and revealing its gaseous composition.
““One of the most exciting results of the last two decades of science about the exoplanet is that so far none of the new planetary systems we’ve discovered are anything like our own solar system,” Burt said. They are full of planets between the size of Earth and Neptune on orbits much shorter than Mercury, so we have no local examples to compare them with. “
Scientists plan to study the planet further later this month using the Hubble Telescope. They also hope to continue their observations and expand their research using, set for launch later this year.
“This new planet we’ve discovered is still weird – but it’s one step closer to being something like our neighborhood planets,” said Burt.