Discovery of an Earth-sized planet in an intriguing solar system
Credits: Artist's representation of exoplanet TOI 700 e. Credits: NASA/JPL-Caltech/Robert Hurt
NASA's TESS satellite has just spotted its second Earth-like planet. This world, which was discovered about 101 light-years from Earth, around the same star as the first, may be able to hold liquid water.
New planet for TESS
Launched just over four years ago, the Transiting Exoplanet Survey Satellite (TESS) has already identified more than 280 confirmed planets (and several thousand candidates). One of the most intriguing is a world named TOI 700 d which was discovered in 2020 . This Earth-sized object is located in the habitable zone of its star, named TOI 700, which is about 101.4 light-years from Earth . More recently, a team from the Jet Propulsion Laboratory identified the presence of a second similar planet also evolving in an area allowing the maintenance of liquid water on the surface.
Note that TOI 700 is a red dwarf star . These objects, which make up about 75% of all stars in the Galaxy, are smaller and cooler than the Sun. On the other hand, they are generally much more active , releasing enormous plumes of plasma likely to destroy all hope of life in the surroundings. However, unlike many of its same-class companions, TOI 700 appears relatively calm (no evidence of flares in two years of data). We could thus imagine favorable conditions for the emergence of life .
TOI 700 is about 95% the size of Earth . The planet is therefore probably rocky. It orbits its star approximately once every 28 Earth days and shows it only one side, like the Moon with the Earth.
Artist's rendering of TOI 700 d. Credits: NASA Goddard Space Flight Center
A compact system
The system also has two other planets moving closer to their star. We could thus make a comparison with the famous TRAPPIST-1 system , found only 39.5 light years from Earth and which is known to bring together seven Earth-sized planets. The TOI 700 system, although more distant, will on the other hand be easier to study insofar as TRAPPIST-1 is a more active and dimmer star.
Researchers are currently observing the system with the Very Large Telescope in Chile using its Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) instrument. The latter, designed to characterize Earth-like exoplanets, could help determine the masses of the four planets in the system. The team also plans to use the James Webb Telescope and focus it on the largest of these planets, TOI 700 b.
This new discovery once again shows the value of TESS' extended mission. The ship was originally supposed to operate for only two years. Its second mission extension, which began last September, will lead it to continue its work until October 2024 .
Source:websites