Chiron ring system
Chiron ring system, Rings of gas and dust are known to encircle Saturn, Jupiter, Uranus, and Neptune.Scientists recently discovered a fifth member of this haloed group known as Chariklo, which is one of a class of minor 'centaur' planets.
Now astronomers have detected a possible ring system around a second centaur, Chiron, suggesting that ringed bodies may be more common in our solar system previously thought.
To discover the rings, the Massachusetts Institute of Technology observed the dimming of a star as Chiron passed in front of it, briefly blocking the light.
By looking at how much and when the light was blocked, scientists say the centaur may possess a circulating disk of debris.
'It's interesting, because Chiron is a centaur - part of that middle section of the solar system, between Jupiter and Pluto, where we originally weren't thinking things would be active, but it's turning out things are quite active,' says Amanda Bosh, a lecturer in MIT's Department of Earth, Atmospheric and Planetary Sciences.
It follows the discovery of rings around a giant asteroid called Chariklo last year.
'I try to imagine how it would be to stand on the surface of this icy object, small enough that a fast sports car could reach escape velocity and drive off into space, and stare up at a 20 kilometer wide ring system 1,000 times closer than the moon,' said Uffe Gråe Jørgensen of the University of Copenhagen of the Chariklo study.
Chiron, discovered in 1977, was the first planetary body categorised as a centaur, after the mythological Greek creature -- a hybrid of man and beast.
Like their mythological counterparts, centaurs are hybrids, embodying traits of both asteroids and comets.
Today, scientists estimate there are more than 44,000 centaurs in the solar system, concentrated mainly in a band between the orbits of Jupiter and Pluto.
While most centaurs are thought to be dormant, scientists have seen glimmers of activity from Chiron.Starting in the late 1980s, astronomers observed patterns of brightening from the centaur, as well as activity similar to that of a streaking comet.
In 2010, MIT started to chart the orbits of Chiron and nearby stars in order to pinpoint exactly when the centaur might pass across a star bright enough to detect.
'There's an aspect of serendipity to these observations,' Professor Bosh says. 'We need a certain amount of luck, waiting for Chiron to pass in front of a star that is bright enough. Chiron itself is small enough that the event is very short; if you blink, you might miss it.'
In light of these new observations, the researchers say that Chiron may still possess symmetrical jets of gas and dust.
But other interpretations may be equally valid, including the 'intriguing possibility,' Professor Bosh says, of a shell or ring of gas and dust.
Ruprecht, who is a researcher at MIT's Lincoln Laboratory, says it is possible to imagine a scenario in which centaurs may form rings.
For example, when a body breaks up, the resulting debris can be captured gravitationally around another body, such as Chiron.
Rings can also be leftover material from the formation of Chiron itself.
Nevertheless, Bosh says the possibility of a second ringed centaur in the solar system is an enticing one.
'Until Chariklo's rings were found, it was commonly believed that these smaller bodies don't have ring systems,' Bosh says.
'If Chiron has a ring system, it will show it's more common than previously thought.'
Now astronomers have detected a possible ring system around a second centaur, Chiron, suggesting that ringed bodies may be more common in our solar system previously thought.
To discover the rings, the Massachusetts Institute of Technology observed the dimming of a star as Chiron passed in front of it, briefly blocking the light.
By looking at how much and when the light was blocked, scientists say the centaur may possess a circulating disk of debris.
'It's interesting, because Chiron is a centaur - part of that middle section of the solar system, between Jupiter and Pluto, where we originally weren't thinking things would be active, but it's turning out things are quite active,' says Amanda Bosh, a lecturer in MIT's Department of Earth, Atmospheric and Planetary Sciences.
It follows the discovery of rings around a giant asteroid called Chariklo last year.
'I try to imagine how it would be to stand on the surface of this icy object, small enough that a fast sports car could reach escape velocity and drive off into space, and stare up at a 20 kilometer wide ring system 1,000 times closer than the moon,' said Uffe Gråe Jørgensen of the University of Copenhagen of the Chariklo study.
Chiron, discovered in 1977, was the first planetary body categorised as a centaur, after the mythological Greek creature -- a hybrid of man and beast.
Like their mythological counterparts, centaurs are hybrids, embodying traits of both asteroids and comets.
Today, scientists estimate there are more than 44,000 centaurs in the solar system, concentrated mainly in a band between the orbits of Jupiter and Pluto.
While most centaurs are thought to be dormant, scientists have seen glimmers of activity from Chiron.Starting in the late 1980s, astronomers observed patterns of brightening from the centaur, as well as activity similar to that of a streaking comet.
In 2010, MIT started to chart the orbits of Chiron and nearby stars in order to pinpoint exactly when the centaur might pass across a star bright enough to detect.
'There's an aspect of serendipity to these observations,' Professor Bosh says. 'We need a certain amount of luck, waiting for Chiron to pass in front of a star that is bright enough. Chiron itself is small enough that the event is very short; if you blink, you might miss it.'
In light of these new observations, the researchers say that Chiron may still possess symmetrical jets of gas and dust.
But other interpretations may be equally valid, including the 'intriguing possibility,' Professor Bosh says, of a shell or ring of gas and dust.
Ruprecht, who is a researcher at MIT's Lincoln Laboratory, says it is possible to imagine a scenario in which centaurs may form rings.
For example, when a body breaks up, the resulting debris can be captured gravitationally around another body, such as Chiron.
Rings can also be leftover material from the formation of Chiron itself.
Nevertheless, Bosh says the possibility of a second ringed centaur in the solar system is an enticing one.
'Until Chariklo's rings were found, it was commonly believed that these smaller bodies don't have ring systems,' Bosh says.
'If Chiron has a ring system, it will show it's more common than previously thought.'