2018 VG18

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2018 VG18
2018VG18-SolarSystem-Orbit.png
Orbit of 2018 VG18 in the Solar System
Discovery [1][2]
Discovered byS. S. Sheppard
D. Tholen
C. Trujillo
Discovery siteMauna Kea Obs.
Discovery date10 November 2018
(first observed only)
Designations
MPC designation2018 VG18
"Farout" (nickname)[3][4]
TNO[5] · SDO[6]
ETNO · distant[2]
Orbital characteristics[5]
Epoch 25 November 2018 (JD 2458447.5)
Uncertainty parameter 9
Observation arc32 days
Aphelion168.7±4225.7 AU
Perihelion21.7±114.0 AU
95.2±2385 AU
Eccentricity0.772±4.925
929±34900 years
73.77°±4021.5°
0° 0m 3.96s / day
Inclination31.7°±145.6°
247.4°±32.6°
32.9°±1107.3°
Physical characteristics
Mean diameter
500 km (est.)[3]
24.6
3.25±0.52[5]

2018 VG18 is the first trans-Neptunian object discovered beyond 100 AU.[4] The object was first observed on 10 November 2018 by astronomers Scott Sheppard, David Tholen, and Chad Trujillo during a search for the hypothetical Planet Nine, and they nicknamed it Farout to emphasize its distance from the Sun.[3]

As of 2018, the object is at an observed distance of ~120 AU. This is more than three times the average distance of Pluto from the Sun, and nearly twice the average distance of Eris. 2018 VG18 is the most distant natural object ever observed in the Solar System, displacing the previous record holder, Eris, at 96 AU. However, it is not close to being the object with the most distant orbit on average, as its semi-major axis is only estimated to be about 95.2 AU; in comparison, the semi-major axis of 2014 FE72 is 1550 AU.

Physical characteristics[edit]

The diameter of 2018 VG18 is estimated to be about 500 km (310 mi), making it a possible dwarf planet.[3] It is pinkish in color.[7]

Nomenclature[edit]

Due to its orbital uncertainty, this object has not yet been assigned an official number. The International Astronomical Union's Minor Planet Center has assigned it the provisional designation 2018 VG18.[1][7] The individuals involved in the object's discovery used the name Farout.[7]

Orbit[edit]

According to the Minor Planet Center, the current heliocentric distance of 2018 VG18 is 125 to 130 AU, but the specific details of the orbit have not yet been established.[1] JPL's Small-Body Database formally estimates it to be currently 125±29 AU from the Sun.[note 1][8] It may take several years of observation to properly characterize the orbit, due to the slow motion of the object.[9]

There are two potential precovery observations (one from 2015, and one from 2017), but the orbital uncertainty needs to be reduced in order to definitively link the current observation arc of 2018 VG18 to these candidate observations.[10]

The orbit of 2018 VG18
Compared to the Solar System (from below the ecliptic)
Compared to Eris and other TNOs. (from above the ecliptic)
Retrograde motion in the sky through Taurus

See also[edit]

Notes[edit]

  1. ^ This formal estimation of its distance from the Sun makes no assumptions about its orbit, simply fitting the observations to any possible orbit, including nearly-impossible ones such as orbits completely unbound to the Sun, Oort-cloud object orbits, and orbits entering the inner solar system.

References[edit]

  1. ^ a b c "MPEC 2018-Y14 : 2018 VG18". Minor Planet Electronic Circular. 17 December 2018. Retrieved 29 December 2018.
  2. ^ a b "2018 VG18". Minor Planet Center. Retrieved 29 December 2018.
  3. ^ a b c d "Discovered: The Most-Distant Solar System Object Ever Observed". Carnegie Science. 17 December 2018. Retrieved 29 December 2018.
  4. ^ a b Chang, Kenneth (17 December 2018). "It's the Solar System's Most Distant Object. Astronomers Named It Farout". The New York Times. Retrieved 29 December 2018.
  5. ^ a b c "JPL Small-Body Database Browser: (2018 VG18)" (2018-12-12 last obs.). Jet Propulsion Laboratory. Retrieved 29 December 2018.
  6. ^ "List Of Centaurs and Scattered-Disk Objects". Minor Planet Center. Retrieved 29 December 2018.
  7. ^ a b c Strickland, Ashley (17 December 2018). "'Farout,' the most-distant solar system object discovered". CNN.com. Retrieved 29 December 2018.
  8. ^ "HORIZONS Web-Interface". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 22 December 2018.
  9. ^ "'Farout!' Newfound Object Is the Farthest Solar System Body Ever Spotted". Space.com. Retrieved 2018-12-18.
  10. ^ Dave Tholen (18 December 2018). "Re: {MPML} 2018 VG18". Retrieved 22 December 2018.
  11. ^ a b "AstDyS-2, Asteroids - Dynamic Site". Retrieved 2018-12-26. Objects with distance from Sun over 59 AU

External links[edit]