Astronomers have unveiled a groundbreaking discovery of a unique ring system around the dwarf planet Quaoar, which is located on the outskirts of our solar system. This unusual ring system, which is far more distant than what is typical for most ring systems, has put established theories of their formation under scrutiny.
The dwarf planet Quaoar, approximately half the size of Pluto and located beyond Neptune's orbit, is the bearer of this intriguing ring system.
The revealing study, featured in Nature, is the result of the collaborative efforts of a global team of astronomers. They utilized HiPERCAM, a high-speed camera of extreme sensitivity, designed by the scientific team at the University of Sheffield. This advanced equipment is affixed to the world's largest optical telescope, the Gran Telescopio Canarias (GTC), which boasts a 10.4-meter diameter and is situated on La Palma.
Given their small size and faint visibility, the rings are not easily discernible in a standard image. Therefore, the researchers observed an occultation - an event where Quaoar obstructs the light from a star in the backdrop as it circles the sun. The brief event, lasting less than a minute, was surprisingly accompanied by two light dips, signaling the presence of a ring system around Quaoar.
Ring systems are a relatively rare phenomenon in our solar system. Beyond the renowned rings of giant planets like Saturn, Jupiter, Uranus, and Neptune, only two other minor planets, Chariklo and Haumea, possess rings. The existing ring systems are able to sustain due to their close proximity to their parent body, which allows tidal forces to prevent the ring material from forming moons.
The uniqueness of Quaoar's ring system lies in the fact that it is positioned at a distance of over seven planetary radii—double the maximum radius previously believed to be possible as per the "Roche limit." This limit was conceived as the maximum distance at which ring systems can survive. To put it into perspective, Saturn's main rings are situated within three planetary radii. This discovery, therefore, necessitates a revision of our current theories on ring formation.
Professor Vik Dhillon, co-author of the study from the University of Sheffield's Department of Physics and Astronomy, stated, "The discovery of this new ring system in our solar system was unexpected, and the rings' distant placement from Quaoar was doubly surprising. This challenges our existing understanding of how such rings come into existence. Our high-speed camera, HiPERCAM, was instrumental in this discovery, as the event was less than a minute long, and the rings are too small and faint for direct observation."
The study was a global collaboration involving 59 academics, led by the Federal University of Rio de Janeiro in Brazil.
Reference:
Bruno Morgado, A dense ring of the trans-Neptunian object Quaoar outside its Roche limit, Nature (2023). DOI: 10.1038/s41586-022-05629-6
You Might Also Like :
0 commenti:
Post a Comment