A newly discovered exoplanet, estimated to have a remarkably mild surface temperature, has suddenly become one of the most interesting objects in our immediate celestial neighborhood. The Venus-sized, rocky world passes by a red dwarf star, providing astronomers with a rare opportunity to study whether such planets can retain their atmospheres and perhaps support life.
Gliese 12 b, similar in size to Venus but slightly smaller than Earth, orbits its cool red dwarf host star, Gliese 12, at only 7% of the Earth-Sun distance. This alarming proximity results in a year lasting only 12.8 days, and the planet receives 1.6 times more energy from its star than Earth does from the Sun. Despite this, Gliese 12 b maintains a surface temperature of 107 degrees Fahrenheit (42 degrees Celsius), making it a temperate world and one of the coldest exoplanets discovered to date, according to new research. research Published today in the Monthly Notices of the Royal Astronomical Society. In comparison, Earth has Average surface temperature The temperature is 59°F (15°C), but is rising due to climate change caused by human activity.
The next big steps for astronomers are to find out whether Gilese 12 b, located 40 light-years from Earth, hosts an atmosphere, and if so what kind it is, and whether the planet is capable of hosting stable liquid water – which A prerequisite for life as we know it – on the surface. “Gliese 12 b represents one of the best targets for studying whether Earth-sized planets orbiting cool stars can retain their atmospheres, a crucial step for advancing our understanding of the habitability of planets across our galaxy,” said Shishir Dholakia, a doctoral student at the center. for Astrophysics at the University of Southern Queensland in Australia, in an emailed statement.
The host star, Gliese 12, is about 27% the size of our Sun, and its surface temperature is about 60% that of our host star. Unlike many red dwarfs, known for their magnetic activity and strong and frequent X-ray flares, Gliese 12 shows no signs of this. Extreme behaviorRaising hopes that Gliese 12 b’s atmosphere may still be intact, according to astronomers.
An exoplanet’s atmosphere (which may or may not exist) will be a key focus of future studies, especially with the James Webb Telescope, which is well-suited to analyzing the chemical composition of planetary atmospheres with its advanced infrared capabilities. Gliese 12 b is a transiting exoplanet, passing frequently in front of its host star from our perspective on Earth, allowing detailed observations through transit spectroscopy. This method enables astronomers to study light filtering through a planet’s atmosphere, revealing the presence of various gases and possible indicators of habitability.
“Although we don’t yet know if it has an atmosphere, we were thinking of it as an exoplanet, with the same size and energy it receives from its star as our planetary neighbor in the solar system,” Masayuki Kuzuhara said. Assistant Professor at the Astrobiology Center in Tokyo. “We have found the closest, transient, temperate, Earth-sized world that exists to date,” he added.
The planet’s location and characteristics can provide insight into why the atmospheres of Earth and Venus are different, despite their similarities. As Dholakia explained: “Atmospheres trap heat and – depending on the type [of atmosphere]- It can change the actual surface temperature significantly.
In the study, the researchers refer to the exoplanet’s “equilibrium temperature,” which is how hot the planet would be without an atmosphere. The main scientific interest in Gliese 12 b is understanding what kind of atmosphere it might have; Ideally, it would have an atmosphere like Earth’s, not the thick, toxic clouds of sulfuric acid found on Venus, where surface temperatures reach more than 860 degrees Fahrenheit (450 degrees Celsius). Since it gets a similar amount of light as Earth and Venus, studying it could help us learn more about the differences between these two planets in our solar system, according to Dholakia.
The researchers used NASA’s Transiting Exoplanet Survey Satellite (TESS) and the European Space Agency’s CHEOPS satellite to estimate the equilibrium temperature of Gliese 12 b. TESS initially discovered the planet by observing its transits, which are periodic dips in starlight caused by the planet passing in front of its host star. These observations were then followed up with more precise measurements from CHEOPS, which helped improve the planet’s orbital period and radius. The combined data from TESS and CHEOPS allowed researchers to calculate the equilibrium temperature by assessing the amount of starlight the planet receives and its distance from the star. The project was a collaborative effort between teams from the University of Southern Queensland, the University of Edinburgh, and the University of Tokyo’s Astrobiology Centre.
The importance of this discovery extends far beyond our solar system. This may help explain whether most of the stars in our Milky Way Galaxy, which are cold red dwarfs, could host temperate planets with atmospheres that would make them habitable. Research from 2013 Proposal As many as 4.5 billion potentially habitable planets may orbit red dwarfs in our galaxy, but evidence to support this has been slim to non-existent.
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The discovery of Gliese 12 b highlights the progress astronomers are making in the search for habitable worlds. While Proxima Centauri b, the closest Earth-like exoplanet at just 4 light-years away, remains poorly understood due to its non-transiting nature, the transit behavior of Gliese 12 b provides a clearer path for atmospheric studies. Hopefully, this feature will allow scientists to gain better insights into its potential habitability.
As research continues to advance, Gliese 12 b could play a pivotal role in our quest to understand the conditions necessary for life outside our solar system.
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