CELLINO, AlbertoAlbertoCELLINOBagnulo, S.S.BagnuloBelskaya, I. N.I. N.BelskayaChristou, A. A.A. A.Christou2020-11-032020-11-0320181745-3925http://hdl.handle.net/20.500.12386/28138We have obtained polarimetric measurements of asteroid (101955) Bennu, a presumably primitive near-Earth object (NEO) that is the target of NASA's sample return mission OSIRIS-REx. During our observing campaign, Bennu was visible from Earth under a wide range of illumination conditions, with phase angle in the range 16°-57°. Together with (3200) Phaethon and (152679) 1998 KU2, observed very recently, Bennu is the only existing example of a primitive NEO observed in polarimetric mode over a wide interval of phase angles. Based on our polarimetric data, we propose that Bennu belongs to the unusual F taxonomic class defined in the 80s. According to previous works, the F-class includes objects with cometary features. This fact can be of great importance for the interpretation of the results of the exploration of this object by OSIRIS-REx. From polarimetry we also derive an estimate of the geometric albedo of Bennu: p<SUB>R</SUB> = 0.059 ± 0.003.STAMPAenArticle10.1093/mnrasl/sly1562-s2.0-85054093412000451569100011https://academic.oup.com/mnrasl/article/481/1/L49/50796422018MNRAS.481L..49CFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation