Unusual polarimetric properties of (101955) Bennu: similarities with F-class asteroids and cometary bodies
arXiv:1808.07812 · doi:10.1093/mnrasl/sly156
Abstract
We 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 to 57 degrees. 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: 0.059 +/- 0.003.
Accepted by MNRAS Letters
References in corpus (8)
- OSIRIS-REx: Sample Return from Asteroid (101955) Bennu
- On the Ages of Resonant, Eroded and Fossil Asteroid Families
- P/2006 VW139: A Main-Belt Comet Born in an Asteroid Collision?
- The phase-polarization curve of asteroid (3200) Phaethon
- Linear spectro-polarimetry: a new diagnostic tool for the classification and characterisation of asteroids
- Expected spectral characteristics of (101955) Bennu and (162173) Ryugu, targets of the OSIRIS-REx and Hayabusa2 missions
- Broadband Linear Polarization of Jupiter Trojans
- Significantly high polarization degree of the very low-albedo asteroid (152679) 1998 KU
Cited by in corpus (11)
- Visible spectroscopy from the Mission Accessible Near-Earth Object Survey (MANOS): Taxonomic dependence on asteroid size
- Dynamical Evolution and Thermal History of Asteroids (3200) Phaethon and (155140) 2005 UD
- Optical spectropolarimetry of binary asteroid Didymos-Dimorphos before and after the DART impact
- Polarimetric Properties of the Near--Sun Asteroid (155140) 2005 UD in Comparison with Other Asteroids and Meteoritic Samples
- (3200) Phaethon Polarimetry in the Negative Branch: New Evidence for the Anhydrous Nature of the DESTINY+ Target Asteroid
- Implications of High Polarization Degree for the Surface State of Ryugu
- Negative polarization properties of regolith simulants -- Systematic experimental evaluation of composition effects
- Optical spectropolarimetry of large C-complex asteroids: polarimetric evidence for heterogeneous surface compositions
- A polarimetric study of asteroids in comet-like orbits
- Quantitative grain size estimation on airless bodies from the negative polarization branch. II. Dawn mission targets (4) Vesta and (1) Ceres
- Revisiting Advanced Thermal Physical Model: New Perspectives on Thermophysical Characteristics of (341843) 2008 EV5 from Four-bands WISE Data with Sunlight-Reflection Model