Today, with all of the high precision instruments and advanced analysis o space, humanity has discovered several potentially habitable planets that supposedly are at the habitable zones of their star systems and can harbor liquid water on their rocky surfaces, and we continue to do so, but mostly we do that around stars that are similar to our own system’s Sun.
Now, researchers found Earth-Sized planets around a star that we refer to as an “ultracool dwarf star”, showing that planets can also be found around low-mass stars, which may point out a good opportunity for habitable worlds to be discovered beyond our own solar system.
These dwarf stars with lower mass are now starting to get attention from researchers, as they are numerous on our galaxy – the Milky Way – and may provide us with a good chance at finding potentially habitable planets, even though most of them are too dim to be seen without the aid of proper tools.
The method known as transit method is what makes spotting planets around stars like these easier, since the habitable zones around these cool dwarf stars is closer than with stars like our Sun.
TRAPPIST, a telescope, used this technique to spot TRAPPIST-1, which sits 40 light-years away from our planet, and since then they found more potentially habitable planets, accounting for a total of 3 planets, with years from 1.5 days to 73 days.
This means the planets are very close to the star, but TRAPPIST-1d gets just the right insulation to have liquid water on the surface.
The proximity to the star means that the planets live in one half in permanent night and the other half in permanent day (like it happens with the moon on Earth) – and we also have to take the atmosphere into account before claiming the world is potentially habitable… by humans at least.