Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581

  title={Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581},
  author={Paul Robertson and Suvrath Mahadevan and Michael Endl and Arpita Roy},
  pages={440 - 444}
Tricky star plays sleight-of-light Two signatures in starlight thought to be written by extrasolar planets may turn out to be forgeries. Astronomers often attribute periodic shifts in a star's apparent motion toward and away from us to the tug of orbiting planets. Robertson et al. studied archival spectra of the star Gliese 581 to assess another potential cause: magnetic activity on the star's surface. The signals once attributed to two planet candidates instead resulted from the combined… 
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