A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10421655" target="_blank" >RIV/00216208:11320/20:10421655 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=pBqWuh5~i8" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=pBqWuh5~i8</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1038/s41550-019-0915-8" target="_blank" >10.1038/s41550-019-0915-8</a>

Result language
angličtina
Original language name
A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea
Original language description
(10) Hygiea is the fourth largest main belt asteroid and the only known asteroid whose surface composition appears similar to that of the dwarf planet (1) Ceres(1,2), suggesting a similar origin for these two objects. Hygiea suffered a giant impact more than 2 Gyr ago(3) that is at the origin of one of the largest asteroid families. However, Hygeia has never been observed with sufficiently high resolution to resolve the details of its surface or to constrain its size and shape. Here, we report high-angular-resolution imaging observations of Hygiea with the VLT/SPHERE instrument (20 mas at 600 nm) that reveal a basin-free nearly spherical shape with a volume-equivalent radius of 217 +/- 7 km, implying a density of 1,944 +/- 250 kg m(-3) to 1 sigma. In addition, we have determined a new rotation period for Hygiea of 13.8 h, which is half the currently accepted value. Numerical simulations of the family-forming event show that Hygiea's spherical shape and family can be explained by a collision with a large projectile (diameter 75-150 km). By comparing Hygiea's sphericity with that of other Solar System objects, it appears that Hygiea is nearly as spherical as Ceres, opening up the possibility for this object to be reclassified as a dwarf planet.
Czech name
—
Czech description
—

Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
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
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Similar results(10)