TY  - JOUR
T1  - Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE
A1  - Fétick, R. JL.
A1  - Jorda, L.
A1  - Vernazza, P.
A1  - Marsset, M.
A1  - Drouard, A.
A1  - Fusco, T.
A1  - Carry, B.
A1  - Marchis, F.
A1  - Hanuš, J.
A1  - Viikinkoski, M.
A1  - Birlan, M.
A1  - Bartczak, P.
A1  - Berthier, J.
A1  - Castillo-Rogez, J.
A1  - Cipriani, F.
A1  - Colas, F.
A1  - Dudziński, G.
A1  - Dumas, C.
A1  - Ferrais, M.
A1  - Jehin, E.
A1  - Kaasalainen, M.
A1  - Kryszczynska, A.
A1  - Lamy, P.
A1  - Le Coroller, H.
A1  - Marciniak, A.
A1  - Michalowski, T.
A1  - Michel, P.
A1  - Mugnier, L. M.
A1  - Neichel, B.
A1  - Pajuelo, M.
A1  - Podlewska-Gaca, E.
A1  - Santana-Ros, T.
A1  - Tanga, P.
A1  - Vachier, F.
A1  - Vigan, A.
A1  - Witasse, O.
A1  - Yang, B.
JA  - Astronomy and Astrophysics
Y1  - 2019
VL  - 623
SP  - A6
SN  - 0004-6361
UR  - https://ui.adsabs.harvard.edu/abs/2019A&A...623A...6F
KW  - asteroids: individual: Vesta
KW  - Astrophysics - Earth and Planetary Astrophysics
KW  - methods: observational
KW  - minor planets
KW  - techniques: high angular resolution
KW  - techniques: image processing
N2  - Context. Over the past decades, several interplanetary missions have
M1  - ={studied small bodies in situ
M1  -  leading to major advances in our
M1  -  understanding of their geological and geophysical properties. These
M1  -  missions
M1  -  however
M1  -  have had a limited number of targets. Among them
M1  -  the
M1  -  NASA Dawn mission has characterised in detail the topography and albedo
M1  -  variegation across the surface of asteroid (4) Vesta down to a spatial
M1  -  resolution of 20 m pixel<SUP>-1</SUP> scale. <BR /> Aims: Here our aim
M1  -  was to determine how much topographic and albedo information can be
M1  -  retrieved from the ground with VLT/SPHERE in the case of Vesta
M1  -  having a
M1  -  former space mission (Dawn) providing us with the ground truth that can
M1  -  be used as a benchmark. <BR /> Methods: We observed Vesta with
M1  -  VLT/SPHERE/ZIMPOL as part of our ESO large programme (ID 199.C-0074) at
M1  -  six different epochs
M1  -  and deconvolved the collected images with a
M1  -  parametric point spread function (PSF). We then compared our images with
M1  -  synthetic views of Vesta generated from the 3D shape model of the Dawn
M1  -  mission
M1  -  on which we projected Vesta's albedo information. <BR />
M1  -  Results: We show that the deconvolution of the VLT/SPHERE images with a
M1  -  parametric PSF allows the retrieval of the main topographic and albedo
M1  -  features present across the surface of Vesta down to a spatial
M1  -  resolution of 20-30 km. Contour extraction shows an accuracy of 1 pixel
M1  -  (3.6 mas). The present study provides the very first quantitative
M1  -  estimate of the accuracy of ground-based adaptive-optics imaging
M1  -  observations of asteroid surfaces. <BR /> Conclusions: In the case of
M1  -  Vesta
M1  -  the upcoming generation of 30-40 m telescopes (ELT
M1  -  TMT
M1  -  GMT)
M1  -  should in principle be able to resolve all of the main features present
M1  -  across its surface
M1  -  including the troughs and the north-south crater
M1  -  dichotomy
M1  -  provided that they operate at the diffraction limit. <P
M1  -  />Reduced images of Table A.1 are only available at the CDS via
M1  -  anonymous ftp to <A
M1  -  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
M1  -  (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-
M1  -  bin/qcat?J/A+A/623/A6">http://cdsarc.u-strasbg.fr/viz-
M1  -  bin/qcat?J/A+A/623/A6</A>Based on observations made with ESO Telescopes
M1  -  at the Paranal Observatory under programme ID 199.C-0074 (PI: P.
M1  -  Vernazza).
M1  -  10.1051/0004-6361/201834749
M1  -  eprint: arXiv:1902.01287}
ER  -