Key facts
- Discovered by
- Deep Ecliptic Survey
- Discovery site
- Cerro Tololo Obs.
- Discovery date
- 22 May 2001
- Pronunciation
- / ɪ k ˈ s aɪ . ə n /
- Named after
- Ιξίων Ixīōn
- Alternative designations
- 2001 KX 76
- Minor planet category
- TNO · plutino · distant
- Adjectives
- Ixionian / ɪ k s i ˈ oʊ n i ə n /
- Symbol
- or (astrological)
- Observation arc
- 39.88 yr (14,565 days)
- Earliest precovery date
- 17 July 1982
- Aphelion
- 49.136 AU
- Perihelion
- 29.858 AU
- Semi major axis
- 39.497 AU
- Orbital period sidereal
- 248.06 yr (90,604 d )
- Mean anomaly
- 294.975 °
- Mean motion
- 0° 0 14.361 / day
- Inclination
- 19.630°
via Wikipedia infobox
Wikidata facts
- Instance of
- plutino
- Named after
- Ixion
- Parent body
- Sun
- Minor-planet group
- plutino
- Distance from Earth
- 28.8151
- Diameter
- 709.6
- Orbital period
- 90162.18397151395
- Image
- 28978-ixion hst.jpg
Show 21 more facts
- discoverer or inventor
- Marc Buie
- Commons category
- 28978 Ixion
- provisional designation
- 2001 KX76
- time of discovery or invention
- 2001-05-22
- orbital inclination
- 19.67041190191546
- site of astronomical discovery
- Cerro Tololo Inter-American Observatory
- orbital eccentricity
- 0.2442328489971719
- apparent magnitude
- 19.84
- absolute magnitude
- 3.47
- periapsis
- 29.73984328588028
- apoapsis
- 48.96123083838791
- semi-major axis of an orbit
- 39.35053706213409
- mean anomaly
- 294.2004612799266
- longitude of ascending node
- 71.09295825377649
- argument of periapsis
- 300.6585723831106
- albedo
- 0.037
- IPA transcription
- ɪkˈsaɪ.ən
- rotation period
- 15.9
- color index
- 1.146
- time of periapsis
- 2477480.028098111
- epoch
- November 21, 2025
via Wikidata · CC0
~16 min read
Encyclopedic overview
28978 Ixion (/ɪkˈsaɪ.ən/; provisional designation 2001 KX76) is a large trans-Neptunian object. It is located in the Kuiper belt, a region of icy objects orbiting beyond Neptune in the outer Solar System. Ixion is classified as a plutino, a dynamical class of objects in a 2:3 orbital resonance with Neptune. It was discovered in May 2001 by astronomers of the Deep Ecliptic Survey at the Cerro Tololo Inter-American Observatory, and was announced in July 2001. The object is named after the Greek mythological figure Ixion, who was a king of the Lapiths.
In visible light, Ixion appears dark and moderately red in color due to organic compounds covering its surface. Water ice has been suspected to be present on Ixion's surface, but may exist in trace amounts hidden underneath a thick layer of organic compounds. Ixion has a measured diameter of 697 km (433 mi), making it the fourth-largest known plutino. It appears to be a transitional object between irregularly-shaped small Solar System bodies and spherical dwarf planets. Ixion is currently not known to have a natural satellite, so its mass and density are unknown.
Excerpted from Wikipedia’s “28978 Ixion” article, available under the CC BY-SA 4.0 licence.