TOI 700 Star system : An analog of Earth found in the habitable zone of red dwarf

Exoplanets around a red dwarf in the artist’s image. Source: NASA

TOI 700 is a small, nearby star system located approximately 101.4 light-years away from Earth, in the constellation Dorado. The TOI 700 is a red dwarf star which is of great interest to astronomers as it contains four exoplanets, including two that are within the habitable zone of the star.

The discovery of TOI 700 and its exoplanets was made using NASA's Transiting Exoplanet Survey Satellite (TESS), which searches for exoplanets by measuring the slight dip in a star's brightness as a planet passes in front of it. The system was first identified as a potential candidate in January 2020 and was later confirmed to have four exoplanets, TOI 700 b, c, d and e.

TOI 700 b is the innermost planet and is the smallest of the three, with a radius only slightly larger than Earth's. It orbits the star in just 10 Earth days and is likely too close to the star to be habitable.

 

TOI 700 c is the middle planet and is over 2.5 times bigger than Earth. It orbits the star in 16 Earth days and is located within the habitable zone, where temperatures may be suitable for liquid water to exist on its surface.The discovery of TOI 700 c within the habitable zone has generated significant interest among astronomers and astrobiologists, as it represents one of the best candidates for finding potentially habitable exoplanets to date. The next step will be to study the planet's atmosphere and determine whether it has the necessary conditions for supporting life.

TOI 700 d is the outermost planet and is the largest of the three, with a radius 1.2 times that of Earth. It orbits the star in 37 Earth days and is likely too cold to support liquid water on its surface.

Using data from NASA’s Transiting Exoplanet Survey Satellite, scientists have identified an Earth-size world, called TOI 700 e, orbiting within the habitable zone of its star – the range of distances where liquid water could occur on a planet’s surface. The world is 95% Earth’s size and likely rocky.

One of the challenges in studying exoplanets like those in the TOI 700 system is the difficulty in obtaining detailed information about their atmospheres. However, advances in technology, such as the James Webb Space Telescope will enable scientists to study the atmospheres of exoplanets in greater detail and may lead to the discovery of signs of life beyond Earth.

The discovery of TOI 700 and its exoplanets represents an exciting development in the search for potentially habitable exoplanets. While much remains to be learned about these planets and their potential for supporting life, the discovery provides a significant boost to the ongoing efforts to understand our place in the universe and the possibility of life beyond Earth.