NASA’s all-sky survey satellite has discovered one its coolest exoplanets to date.
A Neptune-sized planet with an intriguing atmosphere, TOI1231 b was found by scientists from NASA’s Jet Propulsion Laboratory, the University of New Mexico and across the globe.
About 90 light-years away from Earth, TOI-1231 b is expected to join the ranks of just a handful of nearby small exoplanets whose atmospheres are worth being studied by space telescopes.
Both the Hubble Space Telescope (HST) and the upcoming James Webb Space Telescope (JWST) will be used to capture starlight shining through the atmosphere of TOI-1231 b in an effort to detect the gases present.
Due to be published in a future issue of The Astronomical Journal, the paper is based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS), an all-sky survey mission that’s been revealing exoplanets transiting nearby stars since 2018.
TESS mostly finds exoplanets around red dwarf stars, by far the most common kind of star in our Milky Way, which are smaller than the Sun. Almost all of the planets it can detect orbit their stars in 14 days or fewer.
That makes TOI-1231 b special.
NASA's Transiting Exoplanet Survey Satellite (TESS), shown here in a conceptual illustration, will ... [+]
Discovered in the constellation of Vela, TOI-1231 b orbits its star every 24 days. That makes it unusually cool. Researchers estimate that its equilibrium temperature is about 134ºF/57ºC.
“Even though TOI 1231b 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 co-author Diana Dragomir, an assistant professor in UNM’s Department of Physics and Astronomy. “However, the planet itself is actually larger than Earth and a little bit smaller than Neptune—we could call it a sub-Neptune.”
Researchers were able to measure both the radius and mass of the planet, data that allowed them to hypothesize that TOI-1231 b is roughly the size and density of Neptune. “We think it has a similarly large, gaseous atmosphere,” said Jennifer Burt, NASA JPL scientist and the lead author of the paper.
The Hubble Space Telescope will shortly take a closer look at TOI-1231 b in an attempt to tease-out data about the kinds of gases that are swirling around the planet.
However, TOI-1231 b shines mostly in infrared light, which makes it a prime candidate for study by NASA’s upcoming infrared telescope, the $10 billion James Webb Space Telescope (JWST).
An artist's impression shows an exoplanet orbiting the Sun-like star.
“TOI-1231b could have a large hydrogen or hydrogen-helium atmosphere, or a denser water vapor atmosphere,” said Dragomir. “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.”
Planets as cool as TOI-1231 b often have clouds high in their atmospheres, which makes them difficult to study, but recent observations of similarly cool “super-Earth” planet called K2-18 b broke this trend. It’s speculated that K2-18 b has ice-clouds, and possibly water vapor or methane.
So TOI-1231 b will be compared with K2-18 b to allow astronomers to learn how common or rare it is for water clouds to form around temperate worlds.
Astronomers have another advantage because TOI-1231 b appears to be rapidly moving away from us may, which may make it possible to detect hydrogen and helium escaping from its atmosphere.
“None of the new planetary systems we’ve discovered look anything like our own Solar System,” said Burt. “They’re full of planets between the size of Earth and Neptune on orbits much shorter than Mercury’s, so we don’t have any local examples to compare them to.”
TOI-1231 b is different. “This new planet we’ve discovered is still weird, but it's one step closer to being somewhat like our neighborhood planets,” said Burt. “Compared to most transiting planets detected thus far, which often have scorching temperatures in the many hundreds or thousands of degrees, TOI-1231 b is positively frigid.”
Wishing you clear skies and wide eyes.
https://news.google.com/__i/rss/rd/articles/CBMipwFodHRwczovL3d3dy5mb3JiZXMuY29tL3NpdGVzL2phbWllY2FydGVyZXVyb3BlLzIwMjEvMDYvMTIvZXhvcGxhbmV0cy1hbmQtaG90LXdlaXJkLWFuZC1kZWFkLW5vdC10aGlzLW9uZS1zYXktc2NpZW50aXN0cy1hcy10aGV5LXJldmVhbC1hLWNvb2wtd29ybGQtd2l0aC1hbi1hdG1vc3BoZXJlL9IBqwFodHRwczovL3d3dy5mb3JiZXMuY29tL3NpdGVzL2phbWllY2FydGVyZXVyb3BlLzIwMjEvMDYvMTIvZXhvcGxhbmV0cy1hbmQtaG90LXdlaXJkLWFuZC1kZWFkLW5vdC10aGlzLW9uZS1zYXktc2NpZW50aXN0cy1hcy10aGV5LXJldmVhbC1hLWNvb2wtd29ybGQtd2l0aC1hbi1hdG1vc3BoZXJlL2FtcC8?oc=5
2021-06-13 02:00:00Z
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