Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE
| Type of publication: | Article |
| Citation: | |
| Publication status: | Published |
| Journal: | Astronomy and Astrophysics |
| Volume: | 623 |
| Year: | 2019 |
| Month: | mar |
| Pages: | A6 |
| ISSN: | 0004-6361 |
| URL: | https://ui.adsabs.harvard.edu/... |
| Abstract: | Context. Over the past decades, several interplanetary missions have |
| Userfields: | ={studied small bodies in situ, leading to major advances in our, understanding of their geological and geophysical properties. These, missions, however, have had a limited number of targets. Among them, the, NASA Dawn mission has characterised in detail the topography and albedo, variegation across the surface of asteroid (4) Vesta down to a spatial, resolution of 20 m pixel-1 scale. Aims: Here our aim, was to determine how much topographic and albedo information can be, retrieved from the ground with VLT/SPHERE in the case of Vesta, having a, former space mission (Dawn) providing us with the ground truth that can, be used as a benchmark. Methods: We observed Vesta with, VLT/SPHERE/ZIMPOL as part of our ESO large programme (ID 199.C-0074) at, six different epochs, and deconvolved the collected images with a, parametric point spread function (PSF). We then compared our images with, synthetic views of Vesta generated from the 3D shape model of the Dawn, mission, on which we projected Vesta's albedo information. , Results: We show that the deconvolution of the VLT/SPHERE images with a, parametric PSF allows the retrieval of the main topographic and albedo, features present across the surface of Vesta down to a spatial, resolution of 20-30 km. Contour extraction shows an accuracy of 1 pixel, (3.6 mas). The present study provides the very first quantitative, estimate of the accuracy of ground-based adaptive-optics imaging, observations of asteroid surfaces. Conclusions: In the case of, Vesta, the upcoming generation of 30-40 m telescopes (ELT, TMT, GMT), should in principle be able to resolve all of the main features present, across its surface, including the troughs and the north-south crater, dichotomy, provided that they operate at the diffraction limit. |
| Keywords: | asteroids: individual: Vesta, Astrophysics - Earth and Planetary Astrophysics, methods: observational, minor planets, techniques: high angular resolution, techniques: image processing |
| Authors | |
| Added by: | [JoH] |
| Total mark: | 0 |
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