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A NASA mission has detected An Earth-size exoplanet orbiting a small star about 100 light-years away.
The planet TOI 700 e is most likely rocky and 95% larger than our Earth. The celestial body is the fourth planet detected orbiting the small, cold M dwarf star TOI 700. exoplanets It was found by NASA’s Transiting Exoplanet Survey Satellite, or TESS mission.
Another planet in the system, which was discovered in 2020 and called TOI 700 d, is the size of Earth. Both of these exoplanets are in the habitable zone of their star, or just the right distance from the star where liquid water could potentially be found on their surface. The potential for liquid water suggests that planets may be habitable for life or once inhabited.
Discovery of the fourth planet, 241 on Tuesday. American Astronomical Society A study in Seattle and on the exoplanet has been accepted for publication by The Astrophysical Journal Letters.
“This is one of the few systems we know of with multiple, small, habitable zone planets,” lead study author Emily Gilbert, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.
“This makes the TOI 700 system an exciting possibility for additional tracking. Planet e is about 10% smaller than planet d, so the system also shows how additional TESS observations are helping us find increasingly smaller worlds.”
Small, cool M dwarf stars like TOI 700 are common throughout the universe, and many have been found to host exoplanets in recent years. The TRAPPIST-1 system and its seven exoplanets Observed by the James Webb Space Telescope.
Closest to the star, TOI 700 b is 90% Earth’s size and completes a rapid orbit around the star every 10 Earth days. Then there’s TOI 700c, which is 2.5 times larger than our planet and completes one orbit around the star every 16 days. Both of these planets are likely tidally locked, meaning they always point to the same side of the star – just as the same side of the moon always faces Earth.
The two outer planets in the star’s habitable zone, planets d and e, have longer orbits of 37 and 28 days, respectively, as they are slightly further away from the star. The newly announced planet e is actually located between planets c and d.
Launched in 2018, the TESS mission monitors large parts of the night sky for 27 days, looking at the brightest stars and tracking changes in their brightness. These dips in brightness indicate planets orbiting as they pass in front of their so-called transit stars. The mission began observing the southern sky in 2018, then returned to the northern sky. In 2020, the mission refocused on the southern sky for additional observations and revealed the fourth planet in the TOI 700 system.
“If the star were a little closer or the planet was a little larger, we could detect TOI 700 e in the first year of the TESS data,” said study co-author Ben Hord, a PhD student at the University of Maryland. Park and a graduate A researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “But the signal was so weak that we needed an additional year of transit observations to detect it.”
More TESS data is flowing as researchers use other space and ground-based observatories to make follow-up observations of the intriguing planetary system.
“TESS has just completed its second year of northern sky observations,” said Allison Youngblood, research astrophysicist and TESS project scientist at Goddard. “We look forward to other exciting discoveries hidden in the mission’s data trove.”
