Earth-like planet beyond 12.5 light-years

A team of researchers from Carmenes, an international astronomy project to find extraterrestrial planets similar to Earth, discovered two planets from a distance of 12.5 light-years or 118 trillion 260 billion kilometers from the solar system. According to the research team, one of the two planets is likely to have liquid water at a temperature similar to that of Earth.

The two planets discovered this time, Tea Garden b and Tea Garden C, orbit the 15.4 grade Tea Garden’s star in Aries for 4.9 and 11.4 days, respectively. Tea Garden’s star was discovered in 2003, is 12.5 light-years from the Sun, is at least 8 billion years old, and has a mass of only 8-9% of the Sun.

Unlike stars that emit light on their own and can confirm their existence with the naked eye, planets have no choice but to confirm their existence through spectral changes when crossing the star. However, the star activity of Tea Garden is quiet and the brightness is dark, so it is not easy to observe. Carmenes’ team used a 3.5m diameter telescope spectroscope installed at the Cala Alto Observatory in Spain to closely observe the stars in Tigarden for three years. As a result, it is said that it was possible to confirm the existence of tea garden b and tea garden c from more than 200 measurement data.

In the paper, the minimum mass of both planets is close to Earth, contains a lot of iron and water, and the volume is expected to be close to Earth. According to the research team, tea garden b, which orbits the inside of the two planets and is close to a star, can be in a temperate surface environment with temperatures ranging from 0 to 50 degrees Celsius around 28 degrees Celsius. On the other hand, Tea Garden C, orbiting outside, may have a surface temperature of -47 degrees Celsius below Mars.

Experts believe that these two planets are only a little heavier than Earth and belong to the habitable area of living organisms where water can exist in liquid form. In addition, the Earth-like Earth ESI, which is an indicator of how similar a planet or satellite is to the Earth as 1.00, is 0.95 for tea garden b and 0.68 for tea garden c. Tea Garden b is evaluated as the closest planet to Earth among the planets discovered so far. Related information can be found here .