I noticed that in the last days lot of attention was given to this new exoplanets. Well, I guess I have to stay in the “popular sphere” and follow with my post!
Around star called TRAPPIST-1 also known as 2MASS J23062928-0502285 were found together 7 exoplanets, more on this down in the post.
First the star.
Trappist-1 is very small star in special category L which means that it is a red dwarf. You wont find this category in the normal stellar classification because this one and other are made for brown and red dwarfs and were introduced later on. This of course means that Trappist-1 is not very bright or very hot and NOT visible to naked eye (it has apparent magnitude of 18.8 which is way outside of what human eye can see).
The planets were discovered using transit photometry. Method that takes advantage of the planets blocking out some of the star’s light. In 2015 there were 3 discovered already and in February this year, astronomers in Belgium found another 4.
There names are truly beautiful: b,c,d,e,f,g,h (aka. Trappist-1b…)
b,c,e,f,g have similar size to Earth and d,h have radius somewhere between Mars and Earth. e,f,g also orbit in the habitable zone of planet which is an area around the star where liquid water might stay on the surface.
Bit of a problem is that since the planets are so close they receive lot of radiation from Trappist-1 and are also probably tidaly locked, which means that they are facing the star with always the same side, thats what is happening to our Moon too. All of their orbits’ radiuses (semimajor axes) are in matter of few millions of kilometers. For Earth this is 1 AU or 150 millions and for Mercury roughly one third. Their years last few days, for Trappist-1b it is just 1,5 days. Those are definitely some crazy numbers but since we know so little about formation of new life we can not really say how high the probability of something living there is.
NO signals were detected from that direction.
PS: You would have amazing view from the planets since they are so close together.
Source of picture: By NASA/JPL-Caltech – Catalog page · Full-res (JPEG · TIFF), Public Domain, https://commons.wikimedia.org/w/index.php?curid=56513150