Reference:Wikipedia said:A rogue planet is an object which has equivalent mass to a planet and is not gravitationally bound to any star, and that therefore moves through space as an independent object.
Sub-brown dwarf is a planetary-mass object whose mass is smaller than the low-mass cut-off for brown dwarfs (around 13 times the mass of Jupiter). Unlike proper brown dwarfs, they are not massive enough to fuse deuterium. Sub-brown dwarfs are formed in the manner of stars, through the collapse of a gas cloud, and not through accretion or core collapse from a circumstellar disc.
It is theorized that planets can form through a process called gravitational collapse, where gas and dust in a nebula come together through gravity and form into a planet.
It is unlikely that planets without stars can sustain life as they lack a stable energy source. However, some exoplanets known as rogue planets may have the potential to support life through internal heat sources or possible interactions with other objects in the universe.
Yes, there have been several confirmed exoplanets that do not orbit a star. These planets are known as free-floating or rogue planets and are typically detected through their gravitational effects on nearby objects.
Scientists use various methods to detect and study planets without stars, such as using gravitational microlensing, where the planet's gravity causes a brief distortion in the light of a background star. They also use infrared telescopes to observe the heat emitted by these planets.
It is possible for planets without stars to eventually form into stars through a process called accretion. This is where the planet gathers enough mass and density to ignite nuclear fusion and become a star. However, this is a rare occurrence and it is more likely for these objects to remain as free-floating planets.