J/A+A/638/L15ivo://CDS.VizieR/J/A+A/638/L15doi:10.26093/cds/vizier.36389015CDSFerrais M.Vernazza P.Jorda L.Rambaux N.Hanu J.Carry B.,Marchis F.Marsset M.Viikinkoski M.Broz M.Fetick R.Drouard A.,Fusco T.Birlan M.Podlewska-Gaca E.Jehin E.Bartczak P.Berthier J.,Castillo-Rogez J.Cipriani F.Colas F.Dudzinski G.Dumas C.Durech J.,Kaasalainen M.Kryszczynska A.Lamy P.Le Coroller H.Marciniak A.,Michalowski T.Michel P.Santana-Ros T.Tanga P.Vachier F.Vigan A.,Witasse O.Yang B.2020-09-01T10:35:12Z2020-06-29T07:54:10ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsolar-systemasteroidsgalaxy-classification-systemsAsteroid (16) Psyche is the largest M-type asteroid in the main belt and the target of the NASA Psyche mission. It is also the only asteroid of this size (D>200km) known to be metal rich. Although various hypotheses have been proposed to explain the rather unique physical properties of this asteroid, a perfect understanding of its formation and bulk composition is still missing. We aim to refine the shape and bulk density of (16) Psyche and to perform a thorough analysis of its shape to better constrain possible formation scenarios and the structure of its interior. We obtained disk-resolved VLT/SPHERE/ZIMPOL images acquired within our ESO large program (ID 199.C-0074), which complement similar data obtained in 2018. Both data sets offer a complete coverage of Psyche's surface. These images were used to reconstruct the three-dimensional (3D) shape of Psyche with two independent shape modeling algorithms (MPCD and ADAM). A shape analysis was subsequently performed, including a comparison with equilibrium figures and the identification of mass deficit regions. Our 3D shape along with existing mass estimates imply a density of 4.20+/-0.60g/cm^3, which is so far the highest for a solar system object following the four telluric planets. Furthermore, the shape of Psyche presents small deviations from an ellipsoid, that is, prominently three large depressions along its equator. The flatness and density of Psyche are compatible with a formation at hydrostatic equilibrium as a Jacobi ellipsoid with a shorter rotation period of ~3h. Later impacts may have slowed down Psyche's rotation, which is currently ~4.2h, while also creating the imaged depressions. Our results open the possibility that Psyche acquired its primordial shape either after a giant impact while its interior was already frozen or while its interior was still molten owing to the decay of the short-lived radionuclide ^26^Al.2020A&A...638L..15Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/638/L15CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/662/L15 : (22) Kalliope SPHERE images and shape models (Ferrais+, 2022)http://astro.troja.mff.cuni.cz/projects/asteroids3D/web.php : DAMIT Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/638/L15https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/638/L15http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/638/L15https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/638/L15https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/638/L15http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/638/L15GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/638/L15/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/638/L15/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/638/L15/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/638/L15/list?GETtext/xml+votable180.050000true318.11177-14.549710.0055555555555555566/48915 48918 48920https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/638/L15?format=asciiOpticaldefaultJ/A+A/638/L15/spinadamSpin parameter of the ADAM shape modelt0Reference epoch (Julian date, JD)dmeta.ref;time.epochdoublePeriodSidereal rotation periodhtime.perioddoublephi0Initial rotation angle for t0degpos.posAngintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLongPEcliptic longitude of the pole (J2000)degpos.ecliptic.lonfloatLatPEcliptic latitude of the pole (J2000)degpos.ecliptic.latdoubleJ/A+A/638/L15/spinmpcdSpin parameter of the MPCD shape modelrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLongPEcliptic longitude of the pole (J2000)degpos.ecliptic.lonfloatLatPEcliptic latitude of the pole (J2000)degpos.ecliptic.latdoublePeriodSidereal rotation periodhtime.perioddoublet0Reference epoch (Julian date, JD)dmeta.ref;time.epochdoublephi0Initial rotation angle for t0degpos.posAngintJ/A+A/638/L15/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscaleScale of the imagearcsec/pixinstr.scaledoubleNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservatino datestime.epochnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitschar