VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy - Orbital architecture analysis with PyAstrOFitO. Wertz, O. Absil, C. A. Gómez González, J. Milli, J. H. Girard, D. Mawet and L. PueyoA&A, 598 (2017) A83DOI: https://doi.org/10.1051/0004-6361/201628730