10199 Chariklo
Encyclopedia
10199 Chariklo is the largest known centaur. It orbits the Sun between Saturn
and Uranus
, grazing Uranus.
Chariklo was discovered by James V. Scotti
of the Spacewatch
program on February 15, 1997. Chariklo is named after the nymph
Chariclo
(Χαρικλω), the wife of Chiron
and the daughter of Apollo
.
A photometric study in 2001 was unable to find a definite period of rotation. Infrared observations of Chariklo indicate water ice on the surface.
, it is very difficult to estimate their albedos. It is also likely that the albedos of some centaurs vary with time and activity levels.
With an absolute magnitude (H) of 6.4 and an albedo of 0.06, Chariklo is currently the largest known centaur with an estimated diameter of 258 km. 2060 Chiron
(230 km / H=6.5 / albedo=0.07) is likely a close second. Lost centaur (H=6.0) may even be the largest centaur with an estimated diameter of very close to 300 km.
Centaurs are believed to have originated from the Kuiper belt
and are in dynamically unstable orbits that will lead either to ejection from the Solar System, an impact
with a planet or the Sun, or evolution into a short-period comet
.
The orbit of Chariklo is more stable than Nessus
, Chiron
, and Pholus
. Chariklo lies within 0.09 AU
of the 4:3 resonance
of Uranus and is estimated to have a long orbital half-life of about 10.3 Myr
. Twenty clones of Chariklo suggest that Chariklo will not start to regularly come within 3AU (450Gm) of Uranus for about thirty thousand years.
During the perihelic
oppositions of 2003-4, Chariklo had an apparent magnitude
of +17.7. Chariklo is currently 13.7 AU
from the Sun.
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
and Uranus
Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...
, grazing Uranus.
Chariklo was discovered by James V. Scotti
James V. Scotti
James Vernon Scotti is an American astronomer. He was born in Bandon, Oregon and graduated from Woodway Senior High in Edmonds, Washington in 1978. He received his B.Sc. in Astronomy from the University of Arizona in Tucson in 1983. Ever since that time, he has worked on the Spacewatch project,...
of the Spacewatch
Spacewatch
Spacewatch is a project at the University of Arizona led by Robert S. McMillan that specializes in the study of minor planets, including various types of asteroids and comets...
program on February 15, 1997. Chariklo is named after the nymph
Nymph
A nymph in Greek mythology is a female minor nature deity typically associated with a particular location or landform. Different from gods, nymphs are generally regarded as divine spirits who animate nature, and are usually depicted as beautiful, young nubile maidens who love to dance and sing;...
Chariclo
Chariclo
Chariclo is the name of two nymphs in Greek mythology.Chariclo, daughter of Cychreus and Stilbe married Chiron and became the mother of Hippe, Endeis, Ocyrhoe, and Carystus....
(Χαρικλω), the wife of Chiron
Chiron
In Greek mythology, Chiron was held to be the superlative centaur among his brethren.-History:Like the satyrs, centaurs were notorious for being wild and lusty, overly indulgent drinkers and carousers, given to violence when intoxicated, and generally uncultured delinquents...
and the daughter of Apollo
Apollo
Apollo is one of the most important and complex of the Olympian deities in Greek and Roman mythology...
.
A photometric study in 2001 was unable to find a definite period of rotation. Infrared observations of Chariklo indicate water ice on the surface.
Size
If one knows the absolute magnitude (H) and the albedo of an object one can estimate the size. But since centaurs are icy comet-like bodies that may outgasOutgassing
Outgassing is the release of a gas that was dissolved, trapped, frozen or absorbed in some material. As an example, research has shown how the concentration of carbon dioxide in the Earth's atmosphere has sometimes been linked to ocean outgassing...
, it is very difficult to estimate their albedos. It is also likely that the albedos of some centaurs vary with time and activity levels.
With an absolute magnitude (H) of 6.4 and an albedo of 0.06, Chariklo is currently the largest known centaur with an estimated diameter of 258 km. 2060 Chiron
2060 Chiron
2060 Chiron is a minor planet in the outer Solar System. Discovered in 1977 by Charles T. Kowal , it was the first-known member of a new class of objects now known as centaurs, with an orbit between Saturn and Uranus.Although it was initially classified as an asteroid, it was later found to...
(230 km / H=6.5 / albedo=0.07) is likely a close second. Lost centaur (H=6.0) may even be the largest centaur with an estimated diameter of very close to 300 km.
Orbit
Kuiper belt
The Kuiper belt , sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets extending from the orbit of Neptune to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it is far larger—20 times as wide and 20 to 200 times as massive...
and are in dynamically unstable orbits that will lead either to ejection from the Solar System, an impact
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
with a planet or the Sun, or evolution into a short-period comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
.
The orbit of Chariklo is more stable than Nessus
7066 Nessus
7066 Nessus is a centaur that was discovered by David L. Rabinowitz, working with Spacewatch, at Kitt Peak on 26 April 1993. It was the second centaur found by him , and the third centaur discovery...
, Chiron
2060 Chiron
2060 Chiron is a minor planet in the outer Solar System. Discovered in 1977 by Charles T. Kowal , it was the first-known member of a new class of objects now known as centaurs, with an orbit between Saturn and Uranus.Although it was initially classified as an asteroid, it was later found to...
, and Pholus
5145 Pholus
5145 Pholus is a centaur in an eccentric orbit, with a perihelion less than Saturn's and aphelion greater than Neptune's. Pholus has not come within one astronomical unit of a planet since 764 BC, and will not until 5290. It is believed that Pholus originated as a Kuiper belt object.It was...
. Chariklo lies within 0.09 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
of the 4:3 resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
of Uranus and is estimated to have a long orbital half-life of about 10.3 Myr
Myr
The symbol myr was formerly used in English-language geology, and remains as the standard usage in astronomy, as a unit of one million years.It is an abbreviation for 'million years' and lower case is used in geology, while upper case is used in astronomy....
. Twenty clones of Chariklo suggest that Chariklo will not start to regularly come within 3AU (450Gm) of Uranus for about thirty thousand years.
During the perihelic
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
oppositions of 2003-4, Chariklo had an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of +17.7. Chariklo is currently 13.7 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
from the Sun.
External links
- 37th DPS: Albedos, Diameters (and a Density) of Kuiper Belt and Centaur Objects
- AstDys orbital elements
- Orbital simulation from JPL (Java) / Ephemeris
- Chariklo Photo (February 1999)
- Chariklo's orbit between Saturn and Uranus.
- Demonstration of how centaur 10199 Chariklo is currently controlled by Uranus (Solex 10)
