Star

A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the sun. Many other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, the brightest of which were given mythological or zodiacal names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. However, most of the stars in the universe, including all stars outside our galaxy, the Milky Way, are invisible to the naked eye from Earth. Indeed, most are invisible from Earth even through the most powerful telescopes.

A star's engine uses the nuclear fusion of hydrogen into helium to create radiant energy, and this makes them cosmic energy generators. Type II or beyond use stellar engines to gather their energy, or even move them.

An can generally follow two paths (where M = 1 solar mass):


 * Massive star (>8M) --> red supergiant --> supernova --> black hole / neutron star
 * Low-mass star (<8M) --> red giant --> white dwarf