Astronomers from several South American observatories announced today the discovery of a completely unexpected find. Recent observations of the distant minor planet Chariklo revealed that the small body has a ring system.
Chariklo is the smallest body found to date with rings. Joining the much larger planets Jupiter, Saturn, Uranus and Neptune as the fifth known ringed world.
The discovery was made using data from seven different southern telescopes as Chariklo passed in front of star UCAC4 248-108672 on 3 June 2013. Astronomers were able to watch the star vanish for a few seconds as its light was blocked by Chariklo, a technique similar to one used to find extrasolar planets. Instead of what they were expecting a few seconds before and after the main event showed a dip in the brightness of the star, indicating something else was blocking the light.
Further examination of the data indicated that there were in fact two small rings around Chariklo, seven and three kilometres wide, separated by a clear gap of nine kilometres.
“We weren’t looking for a ring and didn’t think small bodies like Chariklo had them at all, so the discovery — and the amazing amount of detail we saw in the system — came as a complete surprise!” says Felipe Braga-Ribas (Observatório Nacional/MCTI, Rio de Janeiro, Brazil) who planned the observation campaign.