How are stars made

BIRTH OF STARS

The picture on the left shows the Crab Nebula. The supernova that created it was observed by Chinese astronomers in AD 1054 and recorded in writing.

After a supernova, what are known as supernova remnants remain. There are many supernova remnants in which neutron stars have been found, for example in the Crab Nebula in the constellation Taurus. Neutron stars rotate very quickly, the neutron star in the Crab Nebula rotates 30 times per second. There are also a few known black holes, such as Cygnus X-1, LMC X-1, and LMC X-3.

Black holes are created when a neutron star becomes more massive. In binary star systems, the neutron star collects mass from its companion. As a result, it develops such a strong force of attraction on the surface that even light can no longer escape. The neutron star has become a black hole.

Smaller stars live much longer. A red dwarf of the M-class lives about 100 billion years, our sun at least 10 billion years (4.5 of which have already passed). They also do not end in a supernova but repel the outer shell which becomes a planetary nebula. The stars end up as an ordinary white dwarf.

Not everything has been clarified about star formation, but research is being continued.