The Kepler space telescope specified the age of the TRAPPIST-1 star, as well as the orbit of the seventh planet of the same system, and the data it obtained indicated the possibility of life there.
An international team of astronomers measured the length of a year on the planet TRAPPIST-1 h, and also determined the age of its star, an ultracold red dwarf. They found that TRAPPIST-1 h, most likely, is only partially suitable for life of the terrestrial type. But its star, it turns out, has existed for 3-8 billion years, and not 0.5 billion, as previously thought. This means that the planets of this system had enough time for complex life to arise on them. The corresponding work is aimed at publication in Nature Astronomy, and its text can be found on the server of the preprints of Cornell University.
The seventh planet of the TRAPPIST-1 system is closer to its star, and that one is 10 times older than it was thought. Life could arise there in 3-8 billion years
Using Kepler's data, astronomers more accurately determined the rotation period of the planet TRAPPIST-1 h around its star: 18.77 Earth days. Previously it was believed that it is equal to 20 days. Thus, the planet was a little closer to its star than it was thought. It receives from the star 200 watts of energy per square meter of surface. In a red dwarf system, liquid water needs 300 watts per square meter for liquid water to exist on the surface. That is, with an atmosphere of terrestrial density, TRAPPIST-1 h is too cold for the existence of life on the surface.
If the atmospheric pressure there is significantly higher than the earth's or the gaseous envelope contains a significant amount of hydrogen, then low illumination should be compensated for by a strong greenhouse effect. Since the planet always looks at the luminary with one side, then at the equator of the illuminated side, the temperature may be sufficient for the existence of liquid water.
In addition, the authors of the work measured the speed of rotation around its axis at the star of the system, the red dwarf TRAPPIST-1. It makes one revolution in 3.3 days. By this parameter, one can roughly determine its age at 3–8 billion years. Previously, the age of the system was determined at only 0.5 billion years, which excluded the possibility of complex life there.
The new estimate increases the age of the planetary system by several times and shows that life there can be quite developed. This is important because TRAPPIST-1 is only 40 light years from Earth and next-generation space telescopes will be able to clarify the composition of the atmospheres of its planets. If there is life there, gases may be present in the gas shells that betray its existence.