Measurement of the polarisation in the auroral N2+ 427.8 nm bandMathieu Barthelemy, Hervé Lamy, Anne Vialatte, Magnar Gullikstad Johnsen, Gaël Cessateur and Naïma ZaourarJ. Space Weather Space Clim., 9 (2019) A26DOI: https://doi.org/10.1051/swsc/2019024