3D shape of asteroid (6) Hebe from VLT/SPHERE imaging: Implications for the origin of ordinary H chondrites

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10371063" target="_blank" >RIV/00216208:11320/17:10371063 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1051/0004-6361/201731021" target="_blank" >http://dx.doi.org/10.1051/0004-6361/201731021</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201731021" target="_blank" >10.1051/0004-6361/201731021</a>

Result language

angličtina

Original language name

3D shape of asteroid (6) Hebe from VLT/SPHERE imaging: Implications for the origin of ordinary H chondrites

Original language description

Context. The high-angular-resolution capability of the new-generation ground-based adaptive-optics camera SPHERE at ESO VLT allows us to assess, for the very first time, the cratering record of medium-sized (D similar to 100-200 km) asteroids from the ground, opening the prospect of a new era of investigation of the asteroid belt&apos;s collisional history. Aims. We investigate here the collisional history of asteroid (6) Hebe and challenge the idea that Hebe may be the parent body of ordinary H chondrites, the most common type of meteorites found on Earth (similar to 34% of the falls). Methods. We observed Hebe with SPHERE as part of the science verification of the instrument. Combined with earlier adaptiveoptics images and optical light curves, we model the spin and three-dimensional (3D) shape of Hebe and check the consistency of the derived model against available stellar occultations and thermal measurements. Results. Our 3D shape model fits the images with sub-pixel residuals and the light curves to 0.02 mag. The rotation period (7.274 47 h), spin (ECJ2000 lambda, beta of 343 degrees, + 47 degrees), and volume-equivalent diameter (193 +/- 6 km) are consistent with previous determinations and thermophysical modeling. Hebe&apos;s inferred density is 3.48 +/- 0.64 g cm(-3), in agreement with an intact interior based on its H-chondrite composition. Using the 3D shape model to derive the volume of the largest depression (likely impact crater), it appears that the latter is significantly smaller than the total volume of close-by S-type H-chondrite-like asteroid families. Conclusions. Our results imply that (6) Hebe is not the most likely source of H chondrites. Over the coming years, our team will collect similar high-precision shape measurements with VLT/SPHERE for similar to 40 asteroids covering the main compositional classes, thus providing an unprecedented dataset to investigate the origin and collisional evolution of the asteroid belt.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy &amp; Astrophysics [online]

ISSN

1432-0746

e-ISSN

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Volume of the periodical

604

Issue of the periodical within the volume

srpen

Country of publishing house

FR - FRANCE

Number of pages

12

Pages from-to

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UT code for WoS article

000408480100129

EID of the result in the Scopus database

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