It is the name of the dwarf star and the planetary system recently discovered by NASA’s Transiting Exoplanet Survey Satellite (TESS). TOI 270 is about 73 light years away from Earth, and is located in the constellation Pictor.
Its members include the dwarf star, which is 40 per cent smaller than the Sun in size and mass, and the three planets or exoplanets (planets outside the solar system) that have been named TOI 270 b, TOI 270 c, and TOI 270 d. These three planets orbit the star every 3.4 days, 5.7 days, and 11.4 days respectively.
In this system, TOI 270 b is the innermost planet. Researchers expect it to be a rocky world about 25 per cent bigger than Earth. It is not habitable since it is located too close to the star — about 13 times closer than our Solar System’s Mercury is from the Sun.
On the other hand, TOI 270 c and TOI 270 d are Neptune-like planets because their compositions are dominated by gases rather than rock. Planet d, which is suspected to have a rocky core covered by a thick atmosphere, offers a surface unfavourably warm for the existence of liquid water, thereby rendering the planet potentially uninhabitable.
With further study and observations, researchers expect to find the composition of these planets, the presence of atmosphere in them and the kinds of gases they contain, etc.