Recent high-resolution images captured by ESO’s Very Large Telescope and the Large Binocular Telescope suggest that the E-type asteroid (44) Nysa is a truly unique entity within our Solar System. Featuring three connected lobes and a recently identified satellite, these findings could shed light on the formation of this extraordinary object.
This image of the Nysa system was captured on February 15, 2026. Image credit: Minker et al., arXiv: 2607.25786.
Nysa stands out as one of the largest and brightest asteroids in the main belt, characterized by its enstatite-like (E-type) surface composition.
This rare classification associates Nysa with enstatite-rich meteorites, including aubrites and enstatite chondrites, suggesting a shared origin with terrestrial planets.
“The images uncover an extraordinarily unusual object,” remarked Dr. Kate Minker, an astronomer at Lowell Observatory.
“Nysa may either be a contact trinary, comprising three interconnected components, or a highly irregular coherent body, distinct from any previously studied.”
“We employed advanced image processing techniques to enhance the images and eliminate the bright halo surrounding the asteroid, which could obscure faint companions,” explained Dr. Anthony Berdeu from ESO.
The team utilized the SPHERE instrument on ESO’s Very Large Telescope and the SHARK-VIS instrument on the Large Binocular Telescope to decipher Nysa’s unique shape.
These sophisticated instruments utilize adaptive optics to counteract atmospheric distortion, facilitating the capture of sharp images of this remarkable asteroid.
“These observations may rival spacecraft-quality imaging achieved from ground-based facilities, thanks to a remarkable combination of advanced equipment and effective data-reduction methodologies,” Dr. Minker commented.
The data indicate that Nysa spans approximately 80 km, displaying three distinct lobes interconnected by two narrower sections, referred to as ‘necks.’
Previous analyses of asteroids with necks categorized them as ‘bilobates,’ featuring only two lobes, while Nysa presents a distinct ‘trilobate’ structure.
The researchers propose two theories regarding Nysa’s peculiar shape:
It may stem from a single object that underwent significant deformation due to collisions or be a composite of three bodies that fused, forming necks at their points of contact.
Further studies are necessary to determine which hypothesis is accurate. For now, astronomers are thrilled to finally unveil Nysa’s structure, which had previously eluded thorough investigation.
“The new images align with several earlier indicators suggesting that Nysa represents a truly unique celestial object,” said Dr. Al Conrad from the Large Binocular Telescope Observatory.
“We can now explore whether these observations point to a deeply indented body or a genuine multi-lobed structure.”
The team’s research paper will appear in the journal Astronomy & Astrophysics.
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Kate Minker et al. 2026. Unmasking (44) Nysa: Evidence for a trilobate structure. A&A, in press; arXiv: 2607.25786
Source: www.sci.news
