The importance of non-photon noise in stellar spectropolarimetry - The spurious detection of a non-existing magnetic field in the A0 supergiant HD 92207S. Bagnulo, L. Fossati, O. Kochukhov and J. D. LandstreetA&A, 559 (2013) A103DOI: https://doi.org/10.1051/0004-6361/201322319
