Those are dwarf stars, which start out as white dwarfs and as they (very slowly) cool, become red dwarfs and eventually brown dwarfs.
Small red stars are called red dwarves. They are the least luminescent and coldest stars.
Of which elements? - Stars usually consist mainly of hydrogen, less helium, and small amounts of the so-called "metals" (which, in astronomy, means any heavier elements).Of which elements? - Stars usually consist mainly of hydrogen, less helium, and small amounts of the so-called "metals" (which, in astronomy, means any heavier elements).Of which elements? - Stars usually consist mainly of hydrogen, less helium, and small amounts of the so-called "metals" (which, in astronomy, means any heavier elements).Of which elements? - Stars usually consist mainly of hydrogen, less helium, and small amounts of the so-called "metals" (which, in astronomy, means any heavier elements).
They are all three. That is why some stars are called White Dwarfs (they are relatively small) and Red Giants or even Supergiants. The Sun is a middle-sized star.
Correct. M-type stars on the main sequence are called red dwarfs.
They are not. A supernova is an explosion of a star. Blue stars usually end their lives in such explosions.
A small group of stars that appear to be close together are often known a cluster. Technically its an asterism.
Those are called "planets". The ancient Greeks distinguished "fixed stars" - which is what we nowadays simply call "stars"; and the moving stars, which in Greek is called "planets".A planet certainly looks like a star (a very bright star, in some cases), but nowadays they are not usually called "stars".
usually the space is measured in light years
This is not a question. There are hundreds of stars in the Universe. Some stars even form many constellations.
It is called a constellation.Constellations.Technically an asterism, but most people usually call it a constellation.
That doesn't make sense. There are stars, and there are planets. If you mean "planets around stars, other than the Sun", those are usually called "extrasolar planets" or "exoplanets".
Small stars live longer