Astronomers Have Spotted The Closest Ever Planet Floating Without A Star

Rouge Planet

Photo: European Southern Observatory

A planet that does not orbit a host star has been found 100 light years from Earth.The planet, named CFBDSIR2149, is known as a “rogue” or “free-floating” planet because it wanders through space free of its parent star. 

Such bodies have been identified before, but what’s exciting about this discovery is that it’s the closest free-floating planet to Earth to have ever been found, giving researchers the opportunity to study its atmosphere in detail.  

The AFP highlights some of CFBDSIR2149’s likely characteristics: 

  • between 50 and 120 million years old
  • has a temperature of around 750 degrees Fahrenheit
  • has a mass of four to seven times that of Jupiter (the biggest planet of our solar system)

A rogue planet is thought to form in two different ways — it either starts as a normal planet and is then kicked out its star system (believed to be the case with CFBDSIR2149) or it begins the same way a star does — from collapsing gas and dust — but does not have enough mass to cause the nuclear fusion that creates starlight.  

“[Rogue planets] are important, as they can either help us understand more about how planets may be ejected from planetary systems, or how very light objects can arise from the star formation process,” lead study author Philippe Delorme said in a news release. “If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space.” 

The findings were published online at arxiv and will appear in the journal Astronomy and Astrophysics. 


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