Asteroid hysteresis can be described as a dwarf planet – and can steal the title of the smallest dwarf planet in the solar system!
Astronomers have captured high-resolution images of Hygia, the fourth largest rock in the asteroid belt, And low and behold, Hygia is a spherical shape. This is a pretty important marker for the dwarf planet, and the only Hygius has been missing so far.
Asteroids take pride in a variety of shapes, but the rounded shape of the dwarf planets shows that they had enough mass for their own gravity to pull it to this circular shape. Hygiene already meets the other requirements for the classification of the dwarf planet, since it orbits the Sun, is not a moon orbiting another planet and has not cleared other objects from its own orbit.
Video: Asteroid Hygiene May Be the Smallest Dwarf Planet in Our Solar System
Related: Meet the Dwarf Planets of the Solar System
So how big is this potential new member of the dwarf planet? The team of astronomers, led by researcher Pierre Vernaca of Laboratoire d & Astrophysique de Marseille in France, limited the size of Hygiea and estimated its diameter to be just over 267 miles (430 kilometers). By comparison, Hygius is less than one-fifth the width of its most famous cousin, Pluto, which has a diameter of about 1491 miles (2400 km).
Ceres holds the title of the smallest dwarf planet so far, with a diameter of nearly 590 miles (950 km).
Before Hygius was officially upgraded to Dwarf Planet, the International Astronomical Union – the same group of astronomers who were responsible for making Pluto a Dwarf planet – must review all the evidence and vote.
Video: Where is the hygiene in our solar system?
"Thanks to these images, Hygia can be reclassified as a dwarf planet, by far the smallest in the solar system," Vernazza said in a statement from the European Southern Observatory (ESO), which runs the SPHERE image-producing tool high resolution in the study. SPHERE (meaning Spectro-Polarimetric High-Contrast Exoplanet Research) sits on top of the very large telescope at the ESO Paranal Observatory in Chile.
"Thanks to the VLT and the new generation of the SPHERE adaptive-optical tool, we are now essentially introducing an asteroid belt with unprecedented resolution, closing the gap between Earth mission observations and interplanetary missions," Vernaca added.
A study detailing the new findings has been published. today (October 28) at Nature Astronomy.