Plutino
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This article is about objects in a 2:3 orbital resonance with Neptune; it is not to be confused with the proposed but rejected IAU term, Plutonian object.
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In astronomy, a plutino is a trans-Neptunian object in 2:3 mean motion resonance with Neptune. Plutinos are named after Pluto, which follows an orbit trapped in the same resonance, with the Italian diminutive suffix -ino. The name refers only to the orbital resonance and does not imply common physical characteristics; it was invented to describe those bodies smaller than Pluto with the resonance (hence the diminutive) but now includes Pluto itself.
Plutinos form the inner part of the Kuiper belt and represent about a quarter of the known Kuiper Belt objects (KBOs). Aside from Pluto itself, the first plutino, 1993 RO, was discovered on September 16, 1993.
The largest plutinos include Pluto, 90482 Orcus, 28978 Ixion, 38083 Rhadamanthus, and 38628 Huya.
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[edit] Orbits
[edit] Origin
It is thought that objects that are currently in mean orbital resonances with Neptune followed initially independent heliocentric paths. During Neptune’s migration (see Kuiper Belt), the objects have been caught into the resonances sweeping outward.[1]
[edit] Orbital characteristics
1For the few large objects whose diameters are known with some precision, the current estimates are shown. For all others, the size of the object plotted is proportional to their absolute magnitude, assuming the albedo.
While the majority of plutinos have low orbital inclinations, a substantial number of them follow orbits similar to that of Pluto, with inclinations in the 10-25o range and eccentricities around 0.2-0.25, resulting in perihelions inside (or close to) the orbit of Neptune and aphelions close to the main Kuiper belt's outer edge (where objects have 1:2 resonance with Neptune).
The orbital periods of plutinos cluster around 247.3 years (1.5 x Neptune's orbital period), varying by at most a few years from this value.
Unusual plutinos include:
- 2005 EK298, which follows the most highly inclined orbit of a plutino (40o)
- 2003 QV91, which has the most elliptical orbit of a plutino (its eccentricity is 0.35, with the perihelion halfway between Uranus and Neptune and the aphelion well into the scattered disk region).
- 2002 KX14, which has a quasi-circular orbit (its eccentricity is 0.04), lying almost perfectly on the ecliptic (inclination less than 0.5o).
See also the comparison with the distribution of the cubewanos.
[edit] Long-term stability
The gravitational influence of Pluto is usually neglected given its small mass. However, the resonance width (the range of semi-axes compatible with the resonance) is very narrow and only a few times larger than Pluto’s Hill sphere (gravitational influence). Consequently, depending on the original eccentricity, some Plutinos will be driven out of the resonance by interactions with Pluto. Numerical simulations suggest that Plutinos with the eccentricity 10%-30% smaller or bigger than that of Pluto are not stable in Ga timescales.[2]
[edit] External links
- David Jewitt (Univ. of Hawaii) on Plutinos
- Minor Planet Center, List of TNOs
- MPC List of Distant Minor Planets
[edit] References
- ^ Malhotra The Origin of Pluto's Orbit: Implications for the Solar System Beyond Neptune Astronomical Journal, 110 (1995), p420. Preprint in arXiv
- ^ Qingjuan Yu and Scott Tremaine The Dynamics of Plutinos The Astronomical Journal, 118 (1999), pp. 1873–1881 Preprint in arXiv
- D.Jewitt, A.Delsanti The Solar System Beyond The Planets in Solar System Update : Topical and Timely Reviews in Solar System Sciences , Springer-Praxis Ed., ISBN 3-540-26056-0 (2006). Preprint of the article (pdf)
- Bernstein G.M., Trilling D.E., Allen R.L. , Brown K.E , Holman M., Malhotra R. The size Distribution of transneptunian bodies. The Astronomical Journal, 128, 1364-1390. preprint on arXiv (pdf)
- Minor Planet Circular 2005-X77 Distant Minor planets was used for plutinos' orbits classification. The updated data can be found in MPC 2006-D28.
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| See also astronomical objects and the solar system's list of objects, sorted by radius or mass. |
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| Plutinos : Pluto* | 1993 RO | 1993 RP | 1993 SB | 1993 SC | 1994 TB | 1995 QZ9 | 1996 SZ4 | 1996 TP66 | 38083 Rhadamanthus | 38628 Huya | 28978 Ixion | 2003 VS2 | 90482 Orcus
Cubewanos: 1998 WW31 | 1992 QB1 | 1994 GV9 | 1994 JQ1 | 1994 VK8 | 1996 TO66 | 19521 Chaos | 53311 Deucalion | 2002 AW197 | 20000 Varuna | 50000 Quaoar | 2002 MS4 | 2002 TX300 | 2002 UX25 | 58534 Logos | 2004 GV9| 2003 EL61 | 2005 FY9 | Unnumbered: 2003 AZ84 | 2003 QW90 | 2005 RN43 Twotinos: Unnumbered: 1996 TR66 | 1998 SM165 | 1997 SZ10 | 1999 RB216 | 2000 JG81 Scattered disc objects: Eris* | 2002 TC302 | 1995 TL8 | 1996 GQ21 | 1996 TL66 | 2000 OO67 | 2000 OM67 | 2001 KC77 | 2001 UR163 | 2002 CY224 | 2002 GX32 | 90377 Sedna** Unnumbered: 2004 XR190 Unclassified Objects : 1994 JS | 1994 JR1 | 1995 DA2 | 1995 SM55 | 1996 TQ66 | 1997 CR29 | 1997 CS29 | 1997 CU29 | 1997 QJ4 | 1998 HJ151 | 1998 HK151 | 1998 HP151 | 1998 HM151 | 1998 KR65 | 1998 SM165 | 1998 SN1651998 US43 | 1998 VG44 | 1998 WW24 | 1998 WA31 | 1998 WU31 | 1998 WA25 | 1999 CP133 | 1999 CL158 | 1999 CC158 | 1999 DF9 | 1999 HT11 | 1999 HB12 | 1999 HC12 | 1999 KR16 | 1999 OY3 Natural satellites : Charon (Pluto) | Hydra (Pluto) | Nix (Pluto) | Dysnomia (Eris) | S/2000 (1998 WW31) 1 | S/2005 (2003 EL61) 1 | S/2005 (2003 EL61) 2 | (58534) Logos I Zoe |
| * - Also classified as a dwarf planet ** - Currently classified as an SDO, though may be part of the Inner Oort Cloud |
