8405 Asbolus

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8405 Asbolus
Discovered by James Scotti and Robert Jedicke
Discovery date 5 April 1995
Named after
1995 GO
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 1
Observation arc 6063 days (16.60 yr)
Aphelion 29.128 AU (4.3575 Tm)
Perihelion 6.8440 AU (1.02385 Tm)
17.986 AU (2.6907 Tm)
Eccentricity 0.61948
76.28 yr (27862 d)
0° 0m 46.516s / day
Inclination 17.640°
Earth MOID 5.87535 AU (878.940 Gm)
Jupiter MOID 2.32867 AU (348.364 Gm)
Jupiter Tisserand parameter 3.071
Physical characteristics
Dimensions 84 ± 8 km (Spitzer) [2]
76 km (Johnston) [3]
Mean radius
33 ± 4 km
8.9351 h (0.37230 d)[1]
0.05 [2]
0.12±0.03 [4]
~ 21.1 [5]

8405 Asbolus (/ˈæzbələs/; from Greek: Άσβολος) is a centaur orbiting between the orbits of Jupiter and Neptune. It was discovered by James 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.


Observations with the Spitzer Space Telescope in 2007 resulted in a diameter calculation of about 84 ± 8 km.[2]

Fresh crater[edit]

No resolved images of it have ever been made, but in 1998 spectral analysis of its composition by the Hubble Space Telescope revealed a fresh impact crater on its surface, less than 10 million years old.[6] 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.


Centaurs have short dynamical lifetimes due to perturbations by the giant planets. Asbolus is estimated to have an orbital half-life of about 860 kiloannum.[7] Asbolus is currently classified as a SN centaur since Saturn is considered to control the perihelion and Neptune controls the aphelion.[7] Asbolus currently has a perihelion (q) of 6.8AU,[1] 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.[7] In about ten thousand years, clones of the orbit of Asbolus suggest that its perihelion classification may come under the control of Jupiter.[8]

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 giants, 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.

This plot shows the variation of the semi-major axis of the unstable Centaur Asbolus during the next 5500 years. You can see that after the Jupiter encounter of year 4713 (27 Cy in the future) the two orbits become substantially divergent.[9]


  1. ^ a b c d "JPL Small-Body Database Browser: 8405 Asbolus (1995 GO)" (February 26, 2008 last obs). Retrieved 13 April 2016. 
  2. ^ a b c John Stansberry; Will Grundy; Mike Brown; Dale Cruikshank; John Spencer; David Trilling; Jean-Luc Margot (2007). "Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope". arXiv:astro-ph/0702538free to read [astro-ph]. 
  3. ^ Wm. Robert Johnston (August 22, 2008). "List of Known Trans-Neptunian Objects". Johnston's Archive. Archived from the original on 16 December 2006. Retrieved December 17, 2006. 
  4. ^ Fernández, Yanga R.; Jewitt, David C.; Sheppard, Scott S. (February 2002). "Thermal Properties of Centaurs Asbolus and Chiron". The Astronomical Journal. 123 (2): 1050–1055. arXiv:astro-ph/0111395free to read. Bibcode:2002AJ....123.1050F. doi:10.1086/338436. 
  5. ^ "AstDys (8405) Asbolus Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved June 28, 2010. 
  6. ^ "Centaur's Bright Surface Spot Could be Crater of Fresh Ice". Hubblesite (STScI-2000-31). September 14, 2000. Retrieved April 12, 2004. 
  7. ^ a b c Horner, J.; Evans, N.W.; Bailey, M. E. (November 2004). "Simulations of the Population of Centaurs I: The Bulk Statistics". Monthly Notices of the Royal Astronomical Society. 354 (3): 798–810. arXiv:astro-ph/0407400free to read. Bibcode:2004MNRAS.354..798H. doi:10.1111/j.1365-2966.2004.08240.x. 
  8. ^ "The perihelion (q) of twenty-two clones of Centaur Asbolus". Retrieved April 26, 2009.  (Solex 10)
  9. ^ "Three clones of Centaur 8405 Asbolus making passes within 450Gm". Retrieved May 2, 2009.  (Solex 10)

External links[edit]