Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581

Abstract

The M dwarf Gliese 581 is believed to host four planets, including one (GJ 581d) near the habitable zone that could possibly support liquid water on its surface if it is a rocky planet. The detection of another habitable-zone planet--GJ 581g--is disputed, as its significance depends on the eccentricity assumed for d. Analyzing stellar activity using the H-alpha line, we measure a stellar rotation period of 130+/-2 days and a correlation for H-alpha modulation with radial velocity. Correcting for activity greatly diminishes the signal of GJ 581d (to 1.5 sigma), while significantly boosting the signals of the other known super-Earth planets. GJ 581d does not exist, but is an artifact of stellar activity which, when incompletely corrected, causes the false detection of planet g.

This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science Express (3 July 2014), doi:10.1126/science.1253253

References in corpus (7)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Habitable planets around the star Gl 581?
• The HARPS search for southern extra-solar planets XI. Super-Earths (5 & 8 M_Earth) in a 3-planet system
• The impact of red noise in radial velocity planet searches: Only three planets orbiting GJ581?
• The Na I D resonance lines in main sequence late-type stars
• A new analysis of the GJ581 extrasolar planetary system
• The All Sky Automated Survey. The Catalog of Variable Stars. IV.18^h - 24^h Quarter of the Southern Hemisphere

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