2001 QR322

Last updated
2001 QR322
Discovery  [1] [2]
Discovered by DES
Discovery site Cerro Tololo Obs.
Discovery date21 August 2001
(discovery: first observation only)
Designations
2001 QR322
Neptune trojan  · L4   [3]
centaur   [1]  · distant   [2]
Orbital characteristics   [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 3
Observation arc 12.26 yr (4,479 days)
Aphelion 30.968 AU
Perihelion 29.262 AU
30.115 AU
Eccentricity 0.0283
165.27 yr (60,363 days)
86.551°
0° 0m 21.6s / day
Inclination 1.3250°
151.75°
151.11°
Physical characteristics
Dimensions110 km (est. at 0.10) [4]
140 km [5]
22.5 [5]
7.9 [1] [3]

    2001 QR322 is a minor planet and the first Neptune trojan discovered on 21 August 2001, by the Deep Ecliptic Survey at Cerro Tololo Observatory in Chile. [2] [6] It orbits ahead of Neptune at its L4 Lagrangian point. [3]

    Contents

    Other Neptune trojans have been discovered since. A study by American astronomers Scott Sheppard and Chad Trujillo from the Carnegie Institution suggests that Neptune could possibly have twenty times more trojans than Jupiter. [7]

    Diameter

    The discoverers estimate that the body has a mean-diameter of 140 kilometers based on a magnitude of 22.5. [5] Based on a generic magnitude-to-diameter conversion, it measures approximately 110 kilometers in diameter using an absolute magnitude of 7.9 and an assumed albedo of 0.10. [4]

    Orbit

    2001 QR322 orbits the Sun with a semi-major axis of 30.115  AU at a distance of 29.3–31.0 AU once every 165 years and 3 months (60,363 days). Its orbit has an eccentricity of 0.03 and an inclination of 1° with respect to the ecliptic. [1]

    Dynamical stability

    Early studies of the dynamical stability of 2001 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 that 2001 QR322 is 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 3σ uncertainties in all six orbital parameters derived from a longer observational arc, has indicated that 2001 QR322 is far less dynamically stable than previously thought. The test particles were lost exponentially with a half life of 553 Myr. Further observations can determine whether 2001 QR322's orbit is actually within the dynamically stable or within the unstable part. [8]

    The stability is strongly dependent on semi-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 larger libration amplitudes, with amplitudes ~70° and above being destabilized by secondary resonances between the trojan motion and the dynamics of at least Saturn, Uranus, and Neptune. Secular resonances were found not to contribute to the dynamical stability of 2001 QR322. [8]

    Numbering and naming

    Due to its orbital uncertainty, this minor planet has not been numbered and its official discoverers have not been determined. [1] [2] If named, it will follow the naming scheme already established with 385571 Otrera, which is to name these objects after figures related to the Amazons, an all-female warrior tribe that fought in the Trojan War on the side of the Trojans against the Greek. [9]

    Related Research Articles

    19521 Chaos

    19521 Chaos is a cubewano, a Kuiper-belt object not in resonance with any planet. It is a possible dwarf planet, but is likely not a solid body. Chaos was discovered in 1998 by the Deep Ecliptic Survey with Kitt Peak's 4 m telescope. Its albedo is 0.050+0.030
    −0.016    , making it, with its absolute magnitude (H) of 4.8, 600+140
    −130     km     in diameter. It is named after the primeval state of existence in Greek mythology, from which the first gods appeared.

    385571 Otrera, provisional designation 2004 UP10, is a Neptune trojan leading Neptune's orbit in the outer Solar System. It was discovered by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory on 16 October 2004. It measures approximately 100 kilometers in diameter and was the second such body to be discovered after 2001 QR322.

    20461 Dioretsa is a centaur and damocloid on a retrograde, cometary-like orbit from the outer Solar System. It was discovered on 8 June 1999, by members of the LINEAR team at the Lincoln Laboratory Experimental Test Site near Socorro, New Mexico, United States. The highly eccentric unusual object measures approximately 14 kilometers in diameter. It was named Dioretsa, the word "asteroid" spelled backwards.

    2005 TN53 is an inclined Neptune trojan leading Neptune's orbit in the outer Solar System, approximately 80 kilometers in diameter. It was first observed on 7 October 2005, by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory in the Atacama desert of Chile. It was the third such body to be discovered, and the first with a significant orbital inclination, which showed that the population as a whole is very dynamically excited.

    385695 Clete, provisional designation 2005 TO74, is a Neptune trojan, co-orbital with the ice giant Neptune, approximately 97 kilometers (60 miles) in diameter. It was named after Clete, one of the Amazons from Greek mythology. The minor planet was discovered on 8 October 2005, by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory in Chile. 23 known Neptune trojans have already been discovered.

    (91205) 1998 US43, provisional designation 1998 US43, is a resonant trans-Neptunian object of the plutino group, located in the Kuiper belt in the outermost region of the Solar System. The rather bluish body measures approximately 111 kilometers (69 miles) in diameter. It was discovered on 22 October 1998, by American astronomer Marc Buie at the Kitt Peak National Observatory in the United States. It is probably not a dwarf planet candidate.

    2006 RJ103 is a Neptune trojan, first observed by the Sloan Digital Sky Survey Collaboration at Apache Point Observatory, New Mexico, on 12 September 2006. It was the fifth and largest such body discovered, approximately 180 kilometers in diameter. As of 2016, it is 30.3 AU from Neptune.

    (527604) 2007 VL305, provisional designation 2007 VL305, is an inclined Neptune trojan that shares Neptune's orbit in the L4 Lagrangian point. It was discovered on 4 November 2007, by astronomers Andrew Becker, Andrew Puckett and Jeremy Kubica at the Apache Point Observatory in New Mexico, United States, although images from 2005 have also been recovered. It measures approximately 160 kilometers in diameter and was the sixth Neptune trojan to be discovered. As of 2016, it is 34.1 AU from Neptune.

    (11436) 1969 QR, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 3.7 kilometers in diameter. It was discovered on 22 August 1969, by Czech astronomer Luboš Kohoutek at Bergedorf Observatory in Hamburg, Germany.

    <span class="nowrap">(528381) 2008 ST<sub>291</sub></span>

    (528381) 2008 ST291, provisional designation 2008 ST291, is a 1:6 resonant trans-Neptunian object and dwarf planet candidate located in the outermost region of the Solar System that takes almost a thousand years to complete an orbit around the Sun. It was discovered on 24 September 2008 by American astronomers Megan Schwamb, Michael Brown and David Rabinowitz at the Palomar Observatory in California, with no known earlier precovery images.

    2008 LC18 is a Neptune trojan first observed on 7 June 2008 by American astronomers Scott Sheppard and Chad Trujillo using the Subaru telescope at Mauna Kea Observatories on Hawaii, United States. It was the first object found in Neptune's trailing L5 Lagrangian point and measures approximately 100 kilometers in diameter.

    2010 KZ39 is a trans-Neptunian object orbiting the Sun as a detached object in the outer reaches of the Solar System. It is likely a dwarf planet as it measures approximately 600 kilometers in diameter. The object was first observed on 21 May 2010 by astronomers Andrzej Udalski, Scott Sheppard, M. Szymanski and Chad Trujillo at the Las Campañas Observatory in Chile.

    2004 KV18 is an eccentric Neptune trojan trailing Neptune's orbit in the outer Solar System, approximately 70 kilometers in diameter. It was first observed on 24 May 2004, by astronomers at the Mauna Kea Observatories on Hawaii, United States. It was the eighth Neptune trojan identified and the second in Neptune's L5 Lagrangian point.

    (523643) 2010 TY53, provisional designation 2010 TY53 is a trans-Neptunian object and centaur located in the outermost region of the Solar System. With an absolute magnitude of 5.7, it approximately measures 325 kilometers (200 miles) in diameter. It was discovered on 4 August 2010 by the Pan-STARRS-1 survey at the Haleakala Observatory, Hawaii, in the United States. According to American astronomer Michael Brown, it is "possibly" a dwarf planet.

    2011 HM102 is the ninth Neptune trojan discovered. It was first observed on 29 April 2011, during the New Horizons KBO Search (268) using the Magellan II (Clay) Telescope at Las Campanas Observatory in Chile. It has the same orbital period as Neptune and orbits at the L5 Lagrangian point about 60° backwards of Neptune.

    (543354) 2014 AN55 (prov. designation:2014 AN55) is a trans-Neptunian object and a dwarf-planet candidate from the scattered disc, located in the outermost region of the Solar System, that measures approximately 600 kilometres (370 mi) in diameter. It was discovered on 25 January 2014, by astronomers with the Pan-STARRS survey at Haleakala Observatory on the island of Maui, Hawaii, in the United States.

    34746 Thoon, prov. designation: 2001 QE91, is a dark Jupiter trojan from the Trojan camp, approximately 60 kilometers (37 miles) in diameter. It was discovered on 22 August 2001, by astronomers with the Lincoln Near-Earth Asteroid Research at Lincoln Lab's ETS in Socorro, New Mexico. The possibly elongated Jovian asteroid is one of the 70 largest Jupiter trojans and has a rotation period of 19.6 hours. It was named after the Trojan warrior Thoön from Greek mythology.

    (20729) 1999 XS143, provisional designation 1999 XS143, is a Jupiter trojan from the Greek camp, approximately 51 kilometers (32 miles) in diameter. It was discovered on 15 December 1999, by American astronomer Charles Juels at the Fountain Hills Observatory in Arizona. The dark Jovian asteroid has a short rotation period of 5.72 hours and belongs to the 90 largest Jupiter trojans. It has not been named since its numbering in January 2001.

    (22149) 2000 WD49, provisional designation 2000 WD49, is a Jupiter trojan from the Greek camp, approximately 50 kilometers (31 miles) in diameter. It was discovered on 21 November 2000, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. The dark Jovian asteroid belongs to the largest Jupiter trojans and has a rotation period of 7.84 hours. It has not been named since its numbering in February 2001.

    2020 XL5 is a sub-kilometer near-Earth asteroid and suspected Earth trojan discovered by the Pan-STARRS 1 survey at Haleakala Observatory, Hawaii on 12 December 2020. In a corotating reference frame with Earth, 2020 XL5's path oscillates about the Sun–Earth L4 Lagrangian point (leading 60°), one of the dynamically stable locations where the combined gravitational force acts through the Sun's and Earth's barycenter. Analysis of 2020 XL5's trojan orbit stability suggests it will remain around Earth's L4 point for several thousand years until gravitational peturbations by Venus destabilize its trojan configuration. It is considered the second Earth trojan discovered, after 2010 TK7 in 2010.

    References

    1. 1 2 3 4 5 6 "JPL Small-Body Database Browser: (2001 QR322)" (2013-11-25 last obs.). Jet Propulsion Laboratory. Archived from the original on 1 September 2020. Retrieved 5 August 2017.
    2. 1 2 3 4 "2001 QR322". Minor Planet Center. Retrieved 5 August 2017.
    3. 1 2 3 "List Of Neptune Trojans". Minor Planet Center. 10 July 2017. Retrieved 4 August 2017.
    4. 1 2 "Asteroid Size Estimator". CNEOS/JPL. Retrieved 2 August 2017.
    5. 1 2 3 Lakdawalla, Emily (13 August 2010). "2008 LC15, the first Trojan asteroid discovered in Neptune's L5 point". The Planetary Society. Retrieved 4 August 2017.
    6. ↑ Marc W. Buie. "Orbit Fit and Astrometric record for 01QR322" (2008-07-21 using 26 of 26 observations). SwRI (Space Science Department). Retrieved 3 September 2009.
    7. ↑ "Neptune May Have Thousands of Escorts". Space.com. 30 January 2007. Retrieved 4 September 2009.
    8. 1 2 3 Horner, 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. S2CID   119241123.
    9. ↑ Ticha, J.; et al. (10 April 2018). "DIVISION F / Working Group for Small Body Nomenclature Working Group for Small Body Nomenclature. THE TRIENNIAL REPORT (2015 Sept 1 - 2018 Feb 15)" (PDF). IAU. Retrieved 25 August 2018.

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