The Earth has two new sisters. They are two potentially habitable planets not far from the Solar System, just over 12 light-years away, in the constellation of Aries, in orbit around the star Teegarden.
The discovery is illustrated in the Carmenes consortium study, published in the journal Astronomy & Atrophysics and coordinated by the German University of Göttingen.
“The aim of the Carmenes project is to find habitable terrestrial-type planets around small stars near the Sun,” explained one of the astronomers, Mancini. The two sisters of the Earth, baptized Teegarden B and C, orbit their mother star in 4.9 and 11.4 days.
Discovered in 2003, the star Teegarden is a red dwarf, the most common type of star in the Milky Way. It is 10 times smaller than the Sun, 1,500 times less luminous and with a temperature around half of our star.
“The two planets – Mancini has clarified – have been found, after three years of observations, with the so-called Doppler technique, that is studying the variation of the radial velocity of the star, in the direction of the observer. Like the variation of the sound of an ambulance approaching or moving away from us”.
The two worlds, with a mass similar to Earth, immediately attracted the attention of researchers. “They are among the most Earth-like planets ever discovered so far“.
One of the two, Teegarden B, has for example the highest index of similarity with the Earth between just over 4,000 worlds outside the Solar System identified so far by scholars. “Both planets – as Mancini pointed out – are in fact, like the Earth, in the so-called habitability zone, the region of space at a distance from the parent star that has the right temperature for the presence of water in the liquid state”.
Future goal is to look directly at these two planets with next-generation telescopes, such as the E-ELT (European-Extremely Large Telescope) of the Southern European Observatory (ESO), and the American TMT (Thirty Meter Telescope).
We will then be able, for example, to understand if they have an atmosphere, in which we can look for possible signs of presence of molecules tied to some sort of life.