8405 Asbolus
Encyclopedia
8405 Asbolus is a centaur, that is, an icy asteroid
that orbits between Jupiter
and Neptune
. It was discovered by James V. Scotti
and Robert Jedicke of Spacewatch
at Kitt Peak Observatory on April 5, 1995. It is named after Asbolus
(Greek for sooty), a centaur
in Greek mythology
. Its provisional designation was 1995 GO.
in 2007 resulted in a diameter calculation of about 84 ± 8 km.
of its composition by the Hubble Space Telescope
revealed a fresh impact crater
on its surface, less than 10 million years old. Centaurs
are dark in colour, because their icy surfaces have darkened after long exposure to solar radiation and the solar wind
. However, fresh craters excavate more reflective ice from below the surface, and that is what Hubble has detected on Asbolus.
by the giant planets. Asbolus is estimated to have an orbital half-life of about 860 kiloannum. Asbolus is currently classified as a SN centaur since Saturn is considered to control the perihelion
and Neptune controls the aphelion. Asbolus currently has a perihelion (q) of 6.8AU, so is also influenced by Jupiter. Centaurs with a perihelion less than 6.6AU are very strongly influenced by Jupiter and for classification purposes are considered to have a perihelion under the control of Jupiter. In about ten thousand years, clones of the orbit of Asbolus suggest that its perihelion classification may come under the control of Jupiter.
Predicting the overall orbit and position of Asbolus beyond a few thousand years is difficult because of errors in the known trajectory
, error amplification by perturbations
due to all of the gas giant
s, and the possibility of perturbation as a result of cometary outgassing/fragmentation. Compared to centaur Nessus
, the orbit of Asbolus is currently much more chaotic.
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
that orbits between Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
and Neptune
Neptune
Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...
. It 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,...
and Robert Jedicke of 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...
at Kitt Peak Observatory on April 5, 1995. It is named after Asbolus
Asbolus
In Greek mythology, Asbolus was a centaur. He was a diviner who read omens in the flight of birds. When Heracles came to visit the centaur Pholus, Pholus opened a jug of wine for him which belonged to all the Centaurs; Asbolus saw Pholus do this and brought the other Centaurs running...
(Greek for sooty), a centaur
Centaur
In Greek mythology, a centaur or hippocentaur is a member of a composite race of creatures, part human and part horse...
in Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
. Its provisional designation was 1995 GO.
Features
Observations with the Spitzer Space TelescopeSpitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
in 2007 resulted in a diameter calculation of about 84 ± 8 km.
Fresh crater
No resolved images of it have ever been made but, in 1998, spectral analysisSpectral analysis
Spectral analysis or Spectrum analysis may refer to:* Spectrum analysis in chemistry and physics, a method of analyzing the chemical properties of matter from bands in their visible spectrum...
of its composition by the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
revealed a fresh impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
on its surface, less than 10 million years old. Centaurs
Centaur (planetoid)
Centaurs are an unstable orbital class of minor planets that behave with characteristics of both asteroids and comets. They are named after the mythological race of beings, centaurs, which were a mixture of horse and human...
are dark in colour, because their icy surfaces have darkened after long exposure to solar radiation and the solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
. However, fresh craters excavate more reflective ice from below the surface, and that is what Hubble has detected on Asbolus.
Orbit
Centaurs have short dynamical lifetimes due to perturbationsPerturbation (astronomy)
Perturbation is a term used in astronomy in connection with descriptions of the complex motion of a massive body which is subject to appreciable gravitational effects from more than one other massive body....
by the giant planets. Asbolus is estimated to have an orbital half-life of about 860 kiloannum. Asbolus is currently classified as a SN centaur since Saturn is considered to control the perihelion
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...
and Neptune controls the aphelion. Asbolus currently has a perihelion (q) of 6.8AU, so is also influenced by Jupiter. Centaurs with a perihelion less than 6.6AU are very strongly influenced by Jupiter and for classification purposes are considered to have a perihelion under the control of Jupiter. In about ten thousand years, clones of the orbit of Asbolus suggest that its perihelion classification may come under the control of Jupiter.
Predicting the overall orbit and position of Asbolus beyond a few thousand years is difficult because of errors in the known trajectory
Trajectory
A trajectory is the path that a moving object follows through space as a function of time. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit—the path of a planet, an asteroid or a comet as it travels around a central mass...
, error amplification by perturbations
Perturbation (astronomy)
Perturbation is a term used in astronomy in connection with descriptions of the complex motion of a massive body which is subject to appreciable gravitational effects from more than one other massive body....
due to all of the gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
s, and the possibility of perturbation as a result of cometary outgassing/fragmentation. Compared to centaur 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...
, the orbit of Asbolus is currently much more chaotic.
External links
- Orbital simulation from JPL (Java) / Ephemeris