28978 Ixion
From Wikipedia, the free encyclopedia
| Discovery | |
|---|---|
| Discovered by: | Deep Ecliptic Survey |
| Discovery date: | 22 May 2001 |
| MPC designation: | 28978 Ixion |
| Alternative names: | 2001 KX76 |
| Minor planet category: | TNO (plutino) |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion distance: | 7370.503 Gm (49.269 AU) |
| Perihelion distance: | 4501.495 Gm (30.091 AU) |
| Semi-major axis: | 5935.999 Gm (39.680 AU) |
| Eccentricity: | 0.242 |
| Orbital period: | 91295.847 d (249.95 a) |
| Avg. orbital speed: | 4.66 km/s |
| Mean anomaly: | 268.546° |
| Inclination: | 19.584° |
| Longitude of ascending node: | 71.028° |
| Argument of perihelion: | 298.779° |
| Physical characteristics | |
| Dimensions: | <822 km diameter |
| Surface area: | <2.24×106 km² |
| Volume: | <3.15×108 km³ |
| Mass: | <5.8×1020? kg |
| Mean density: | 2.0? g/cm³ |
| Equatorial surface gravity: | <0.2297? m/s² |
| Escape velocity: | <0.4346? km/s |
| Rotation period: | ? d |
| Albedo: | 0.15 |
| Temperature: | ~44 K |
| Spectral type: | (moderately red; B-V=1.03, V-R=0.61) |
| Absolute magnitude: | 3.244 |
28978 Ixion (IPA pronunciation: [ɪk'saɪ.ɒn], Wiktionary:Ixion) is a Kuiper belt object discovered on May 22, 2001. Ixion is a plutino (an object that has a 2:3 orbital resonance with Neptune); its estimated diameter of 800 km makes it the second largest plutino. It is named after Ixion, a figure from Greek mythology; it previously had the provisional designation 2001 KX76.
Contents |
[edit] Physical characteristics
Ixion is moderately red (slightly redder than 50000 Quaoar) and it has a higher albedo (0.15) than the mid-sized red cubewanos.
The latest spectroscopic results indicate that Ixion's surface is a mixture of dark carbon and tholin, which is a heteropolymer formed by irradiation of clathrates of water and organic compounds (see TNO spectra). Water ice absobtion lines (1.5 and 2μm) were absent (Licandro et al. 2002). Unlike Varuna, Ixion does not show greater reflectivity for longer waves (the so-called red slope) in infrared.
[edit] Orbit
Ixion and Pluto follow similar but differently oriented orbits: Ixion’s perihelion is below the ecliptic whereas Pluto's is above it. Uncharacteristically for bodies locked in resonance with Neptune (such as Orcus), Ixion approaches Pluto with less than 20 degrees of angular separation. Ixion is currently crossing the ecliptic heading below, and will reach its perihelion in 2070. Pluto has passed its perihelion (1989) and is descending toward the ecliptic.
[edit] See also
[edit] References
- H. Boehnhardt, S. Bagnulo, K. Muinonen, M. A. Barucci, L. Kolokolova, E. Dotto and G. P. Tozzi (2003). "Surface characterization of 28978 Ixion (2001 KX76)". Astronomy & Astrophysics 415: L17-L19. Pre-print about Ixion's surface from the Planetary Systems Research group of the University of Helsinki
- J. Licandro, F. Ghinassi, L. Testi (2002). "Infrared spectroscopy of the largest known trans-neptunian object 2001 KX76". Astronomy & Astrophysics. Pre-print on arXiv
- W. J. Altenhoff, F. Bertoldi and K. M. Menten (2004). "Size estimates of some optically bright KBOs". Astronomy & Astrophysics 415.
[edit] External links
- AstDys orbital elements
- Orbit simulation from JPL (Java).
| Minor planets | ||
|---|---|---|
| Previous minor planet | 28978 Ixion | Next minor planet |
| List of asteroids | ||
Kuiper belt: Orcus · Pluto · Ixion · 2002 UX25 · Varuna · 2002 TX300 · 2003 EL61 · Quaoar · 2005 FY9 · 2002 AW197
Scattered disc: 2002 TC302 · Eris · 2004 XR190 · Sedna
For pronunciation, see: Centaur and TNO pronunciation.
Vulcanoids · Near-Earth asteroids · Main belt · Jupiter Trojans · Centaurs · Damocloids · Comets · Trans-Neptunians (Kuiper belt • Scattered disc • Oort cloud)
For other objects and regions, see Asteroid groups and families, Binary asteroids, Asteroid moons and the Solar System.
For a complete listing, see List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names.
