SIMBAD references

Recent studies indicate that Gliese 581d, a proposed habitable zone (HZ) super-Earth planet, does not exist, as the respective data denote that the planet is an artifact of stellar activity. Here we report evidence to the contrary considering that those studies were based on inaccurate spectroscopic measurements of the stellar rotation period regarding the planet's inactive host star (dM3). Gliese 581d, if real, is of particular interest as it constitutes the first planet identified to be in a stellar HZ outside of the solar system based on studies in 2007. If confirmed as a true planet, at 20.5 lt-yr, it would also be one of the nearest potentially habitable super-Earths.