Subestelares

Subestelares is a term used in astronomy to describe objects that are less massive than stars but more massive than planets. These objects, often referred to as brown dwarfs, occupy a unique niche in the celestial hierarchy. They are not massive enough to sustain nuclear fusion of hydrogen in their cores, the defining characteristic of a true star. However, they are massive enough to fuse deuterium, a heavier isotope of hydrogen, for a period of their existence.

The mass range for subestelares typically falls between approximately 13 times the mass of Jupiter and about 75 to 80 times the mass of Jupiter. Objects below this range are generally considered planets, especially if they form through planetary formation processes rather than stellar or substellar formation. Above this range, objects are classified as stars, capable of hydrogen fusion.

Subestelares were once theoretical objects, predicted to exist by stellar evolution models. Their discovery in the 1990s confirmed their existence and opened up a new area of astrophysical research. Studying subestelares provides valuable insights into the low-mass end of the stellar initial mass function and the processes of star and planet formation. They can also be found in binary systems with stars or other brown dwarfs, and their atmospheres can exhibit unique spectral features due to the presence of molecules like methane and water.