The impact crater at the origin of the Julia family detected with VLT/SPHERE?

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10385765" target="_blank" >RIV/00216208:11320/18:10385765 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1051/0004-6361/201833477" target="_blank" >https://doi.org/10.1051/0004-6361/201833477</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201833477" target="_blank" >10.1051/0004-6361/201833477</a>

Result language

angličtina

Original language name

The impact crater at the origin of the Julia family detected with VLT/SPHERE?

Original language description

Context. The vast majority of the geophysical and geological constraints (e.g., internal structure, cratering history) for main-belt asteroids have so far been obtained via dedicated interplanetary missions (e.g., ESA Rosetta, NASA Dawn). The high angular resolution of SPHERE/ZIMPOL, the new-generation visible adaptive-optics camera at ESO VLT, implies that these science objectives can now be investigated from the ground for a large fraction of D &gt;= 100 km main-belt asteroids. The sharp images acquired by this instrument can be used to accurately constrain the shape and thus volume of these bodies (hence density when combined with mass estimates) and to characterize the distribution and topography of D &gt;= 30 km craters across their surfaces. Aims. Here, via several complementary approaches, we evaluated the recently proposed hypothesis that the S-type asteroid (89) Julia is the parent body of a small compact asteroid family that formed via a cratering collisional event. Methods. We observed (89) Julia with VLT/SPHERE/ZIMPOL throughout its rotation, derived its 3D shape, and performed a reconnaissance and characterization of the largest craters. We also performed numerical simulations to first confirm the existence of the Julia family and to determine its age and the size of the impact crater at its origin. Finally, we utilized the images/3D shape in an attempt to identify the origin location of the small collisional family. Results. On the one hand, our VLT/SPHERE observations reveal the presence of a large crater (D similar to 75 km) in Julia&apos;s southern hemisphere. On the other hand, our numerical simulations suggest that (89) Julia was impacted 30-120 Myrs ago by a D similar to 8 km asteroid, thereby creating a D &gt;= 60 km impact crater at the surface of Julia. Given the small size of the impactor, the obliquity of Julia and the particular orientation of the family in the (a,i) space, the imaged impact crater is likely to be the origin of the family. Conclusions. New doors into ground-based asteroid exploration, namely, geophysics and geology, are being opened thanks to the unique capabilities of VLT/SPHERE. Also, the present work may represent the beginning of a new era of asteroid-family studies. In the fields of geophysics, geology, and asteroid family studies, the future will only get brighter with the forthcoming arrival of 30-40 m class telescopes like ELT, TMT, and GMT.

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

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

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

618

Issue of the periodical within the volume

Neuveden

Country of publishing house

FR - FRANCE

Number of pages

16

Pages from-to

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UT code for WoS article

000447965300001

EID of the result in the Scopus database

2-s2.0-85056083227