28978 Ixion

28978 Ixion (Ixion) is a Kuiper belt object discovered on May 22, 2001. With a diameter estimated at 800 km Ixion is the second largest plutino, i.e. it follows an orbit similar to Pluto in 2:3 orbital resonance with Neptune.

Little is known about this object. The object is moderately red (slightly redder than 50000 Quaoar) and has a higher albedo (0.15) compared with the mid-sized red classical objects: 0.10 and 0.04 for Quaoar and 20000 Varuna respectively (see colour comparisons).

The latest spectroscopy results indicate that the Ixionian surface is a mixture of dark carbon and tholin, which is a heteropolymer formed by irradiation of clathrates of water and organic compounds (More on possible spectra interpretations).

The infrared spectrum was found flat (did not show the red slope of Varuna) and water ice absobtion lines (1.5 and 2μm) were absent (Licandro et al. 2002).

28978 Ixion is named after Ixion, a figure from Greek mythology. It previously had the provisional designation .

Orbit

Ixion and Pluto follow similar but differently oriented orbits as shown on the diagram (Ixion in green , Pluto in red, Neptune in grey, the positions as of April 2006). Ixion’s perihelion is below the ecliptic. Uncharacteristically for the bodies locked in the resonance (see Orcus), Ixion approaches Pluto with less than 20 degrees angular separation. Ixion is currently crossing the ecliptic heading below, and will reach its perihelion in 2070. Pluto has passed the perihelion (1989) and is descending toward the ecliptic.

External links

AstDys orbital elements
Orbit simulation from JPL (Java).

References

Pre-print about Ixion's surface from the Planetary Systems Research group of the University of Helsinki

Pre-print on arXiv

Trans-Neptunian objects

Gourt Home::Gourt :: 28978 Ixion

Orbit

External links

References