 Gliese 581 g / ˈɡliːzə / , ( also known as Gl 581 g or GJ 581 g ) , unofficially known as Zarmina , is an unconfirmed ( and disputed ) exoplanet claimed to orbit the red dwarf Gliese 581 , about 20 light @-@ years from Earth in the constellation of Libra . It is the sixth planet purportedly discovered orbiting the star . The discovery was announced by the Lick @-@ Carnegie Exoplanet Survey in late September 2010 , after a decade of observation . However , the ESO / HARPS survey team was not able to confirm that the planet exists . 
