(612243) 2001 QR322
 | |
| Discovery[1] | |
|---|---|
| Discovered by | M. W. Buie(DES) |
| Discovery site | Cerro Tololo Obs. |
| Discovery date | 21 August 2001 |
| Designations | |
| (612243) 2001 QR322 | |
| 2001 QR322 | |
| Neptune trojan·L4[2] TNO[3]·distant[1] | |
| Orbital characteristics[3] | |
| Epoch4 September 2017 (JD2458000.5) | |
| Uncertainty parameter3 | |
| Observation arc | 12.26 yr (4,479 days) |
| Aphelion | 30.968AU |
| Perihelion | 29.262 AU |
| 30.115 AU | |
| Eccentricity | 0.0283 |
| 165.27yr(60,363 days) | |
| 86.551° | |
| 0° 0m21.6s/ day | |
| Inclination | 1.3250° |
| 151.75° | |
| 151.11° | |
| Physical characteristics | |
| 132km[4] | |
| 0.058[4] | |
| 22.5[5] | |
| 8.12[3][2] | |
(612243) 2001 QR322,prov. designation:2001 QR322,is aminor planetand the firstNeptune trojandiscovered, by American astronomerMarc Buieof theDeep Ecliptic SurveyatCerro Tololo Observatoryin Chile on 21 August 2001.[1][6]It orbits ahead of Neptune at itsL4Lagrangian pointand measures approximately 132 kilometers (82 miles) in diameter.[2][4]
Other Neptune trojans have been discovered since. A study by American astronomersScott SheppardandChad Trujillofrom the Carnegie Institution suggests that Neptune could possibly have twenty times more trojans than Jupiter.[7]
Orbit[edit]
2001 QR322orbits the Sun with a semi-major axis of 30.115AUat a distance of 29.3–31.0 AU once every 165 years and 3 months (60,363 days). Its orbit has aneccentricityof 0.03 and aninclinationof 1°with respect to theecliptic.[3]
Dynamical stability[edit]
Early studies of the dynamical stability of2001 QR322,which used a small number of test particles spread over the uncertainties of just a few orbital parameters that were derived from a limited observation arc, suggested that2001 QR322is on a remarkably stable orbit, because most test particles remained on trojan orbits for 5 Gyr. Thereafter, the stability of Neptune trojans was simply assumed.[8]
A more recent study, which used a very large number of test particles spread over the 3σuncertainties in all six orbital parameters derived from a longer observational arc, has indicated that2001 QR322is far less dynamically stable than previously thought. The test particles were lost exponentially with ahalf lifeof 553 Myr. Further observations can determine whether2001 QR322's orbit is actually within the dynamically stable or within the unstable part.[8]
The stability is strongly dependent onsemi-major axis,with a≥30.30 AU being far less stable, but only very weakly dependent on the other orbital parameters. This is because those with larger semi-major axes have largerlibrationamplitudes, with amplitudes ~70° and above being destabilized by secondary resonances between the trojan motion and the dynamics of at leastSaturn,Uranus,and Neptune.Secular resonanceswere found not to contribute to the dynamical stability of2001 QR322.[8]
Numbering and naming[edit]
Thisminor planetwasnumberedand itsdiscovererdetermined by theMinor Planet Centeron 28 March 2022 (M.P.C.139893).[1][9]If named, it will follow the naming scheme already established with385571 Otrera,which is to name these objects after figures related to theAmazons,an all-female warrior tribe that fought in theTrojan Waron the side of the Trojans against the Greek.[10]
Physical characteristics[edit]
The discoverers estimate that the body has amean diameterof 132 kilometers with a lowalbedoof 0.058 at anabsolute magnitudeof 8.12.[4]It has a visualmagnitudeof 22.5.[5]
References[edit]
- ^abcd"(612243) 2001 QR322".Minor Planet Center.Retrieved8 April2022.
- ^abc"List of Neptune Trojans".Minor Planet Center.10 July 2017.Retrieved4 August2017.
- ^abcd"JPL Small-Body Database Browser: (2001 QR322)"(2013-11-25 last obs.).Jet Propulsion Laboratory.Archived fromthe originalon 1 September 2020.Retrieved5 August2017.
- ^abcdJohnston, Wm. Robert (2 January 2022)."List of Known Trans-Neptunian Objects".Johnston's Archive.
- ^abLakdawalla, Emily (13 August 2010)."2008 LC15, the first Trojan asteroid discovered in Neptune's L5 point".The Planetary Society.Retrieved8 April2022.
- ^Marc W. Buie."Orbit Fit and Astrometric record for 01QR322"(2008-07-21 using 26 of 26 observations). SwRI (Space Science Department).Retrieved3 September2009.
- ^"Neptune May Have Thousands of Escorts".Space.30 January 2007.Retrieved4 September2009.
- ^abcHorner, J.; Lykawka, P. S. (June 2010). "2001 QR322: a dynamically unstable Neptune Trojan?".Monthly Notices of the Royal Astronomical Society.405(1): 49–56.arXiv:1002.4699.Bibcode:2010MNRAS.405...49H.doi:10.1111/j.1365-2966.2010.16441.x.S2CID119241123.
- ^"MPC/MPO/MPS Archive".Minor Planet Center.Retrieved8 April2022.
- ^"Rules and Guidelines for naming non-cometary small Solar-System bodies – v1.0"(PDF).Working Group Small Body Nomenclature(PDF). 20 December 2021.
External links[edit]
- (612243) 2001 QR322atAstDyS-2, Asteroids—Dynamic Site
- (612243) 2001 QR322at theJPL Small-Body Database
