(208996) 2003 AZ84

(208996) 2003 AZ84
2003 AZ84 and its possible satellite, imaged by the Hubble Space Telescope on 2 December 2005.
Discovery[1][2]
Discovered byC. Trujillo
M. E. Brown
Discovery siteNEAT–Palomar Obs.
Discovery date13 January 2003
Designations
2003 AZ84
TNO[1] · plutino[3] · distant[4]
Orbital characteristics[1]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 3
Observation arc20.96 yr (7,654 days)
Earliest precovery date19 March 1996
Aphelion46.555 AU
Perihelion32.170 AU
39.362 AU
Eccentricity0.183
246.96 yr (90,202 days)
232.611°
0° 0m 14.368s / day
Inclination13.596°
252.202°
≈ 27 March 2107[5]
±2.2 days
15.211°
Known satellites1[6] (diameter: 72 km)[7][8]
(unrecovered)[9]
Physical characteristics
Dimensions? (940±40)×(766±20)×(490±16) km (derived from assumption of hydrostatic equilibrium)[10]
? 772±12 km (assuming HE)[10]
723 km (for albedo 0.097)[7]
Mass? 210×1018 kg (derived from [10])
150×1018 kg (derived from [7])
Mean density
? 0.87±0.01 g/cm3 (assuming HE)[10]
0.76 g/cm3[7]
6.7874±0.0002 h[11]
? 0.097±0.009 (assuming HE)[10]
0.097[7]
20.3 (opposition)[12]
3.760±0.058 (V)[11]
3.537±0.053 (R)[13]

(208996) 2003 AZ84 (provisional designation 2003 AZ84) is a trans-Neptunian object with a possible moon[6][9] located in the outer regions of the Solar System. It is approximately 940 kilometers across its longest axis, as it has an elongated shape.[10] It belongs to the plutinos – a group of minor planets named after its largest member Pluto – as it orbits in a 2:3 resonance with Neptune in the Kuiper belt.[3][14] It is the third-largest known plutino, after Pluto and Orcus. It was discovered on 13 January 2003, by American astronomers Chad Trujillo and Michael Brown during the NEAT survey using the Samuel Oschin telescope at Palomar Observatory.[4]

Though elongated in shape, 2003 AZ84 displays a small lightcurve amplitude due to its rotation axis being oriented nearly pole-on; the variability is mainly caused by albedo features on its surface.[11][10]

It is considered a very likely dwarf planet by astronomers Gonzalo Tancredi and Michael Brown.[15][16] However, Will M. Grundy et al. conclude that objects such as this, in the size range of 400–1,000 km, with albedos less than ≈0.2 and densities of ≈1.2 g/cm3 or less, have likely never compressed into fully solid bodies, let alone differentiated or collapsed into hydrostatic equilibrium, and so are highly unlikely to be dwarf planets.[17]

  1. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference MPEC2002-V26 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Buie was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference MPC-208996 was invoked but never defined (see the help page).
  5. ^ JPL Horizons Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 3-sigma.)
  6. ^ a b Cite error: The named reference IAUC-8812 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference JA was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference johnston was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference plutokiller was invoked but never defined (see the help page).
  10. ^ a b c d e f g Cite error: The named reference Dias-Oliveira-2017 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference TNOsCool12 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference AstDys was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Peixinho-2012 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference MPEC2009-P26 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Tancredi was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Brown-dplist was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Grundy2019 was invoked but never defined (see the help page).