sentences:  A study in 2014 concluded that Gliese 581d is "an artifact of stellar activity which, when incompletely corrected, causes the false detection of planet g." In 2015, a study by Guillem Anglada-Escudé and Mikko Tuomi discounted the 2014 analysis and concluded that the planet could exist and confirmed the planet.If finally verified, Gliese 581d would constitute the first planet identified to be located in a stellar habitable zone outside of the Solar System, based on studies of 2007.Gliese 581d orbits Gliese 581 at 0.21847 AU, approximately a fifth of the distance that the Earth orbits the Sun, though its orbital eccentricity has not been confirmed.