(432949) 2012 HH2

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(432949) 2012 HH2
Discovery animation of the TNO 2012 HH2.gif
Discovery animation by the Astronomical Research Institute of 2012 HH2
Discovery[1]
Discovered byT. Vorobjov
Discovery siteAstronomical Research Institute (H21)
Discovery date19 April 2012
Designations
(432949) 2012 HH2
2012 HH2
Minor planet category
TNO[2] · res 4:5[3][4]
Orbital characteristics[2]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 2
Observation arc19.16 yr (6,998 d)
Aphelion40.414 AU
Perihelion29.201 AU
34.808 AU
Eccentricity0.1611
205.36 yr (75,008 d)
40.568°
0° 0m 17.28s / day
Inclination28.585°
56.464°
100.49°
Physical characteristics
Mean diameter
255 km (est.)[3]
0.09 (est.)[3]
Absolute magnitude (H)
6.38[1][2]

(432949) 2012 HH2 is a resonant trans-Neptunian object, approximately 255 kilometers (160 miles) in diameter, located in the outermost region of the Solar System.[3] It was discovered by Slovak astronomer Tomáš Vorobjov from images taken on the night of 19 April 2012, at the Astronomical Research Institute (H21) in Illinois, United States.

Orbit and classification[]

2012 HH2 is a resonant trans-Neptunian object in an uncommon 4:5 resonance with Neptune (DES: 5:4E).[3][4] It orbits the Sun at a distance of 29.2–40.4 AU once every 205 years and 4 months (75,008 days; semi-major axis of 34.81 AU). Its orbit has an eccentricity of 0.16 and an inclination of 29° with respect to the ecliptic.[2] It is currently 29.8 AU from the Sun.

Numbering and naming[]

This minor planet was numbered (432949) by the Minor Planet Center on 4 April 2015 (M.P.C. 93615).[5] As of 2021, it has not been named.

Physical characteristics[]

Rotation period[]

As of 2021, no rotational lightcurve of 2012 HH2 has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.[2]

Diameter and albedo[]

Johnston's Archive estimates a mean-diameter of 255 kilometers (160 miles), using a standard magnitude-to-diameter conversion with an assumed albedo of 0.09.[3] Astronomer Mike Brown gives a nearly identical estimates of 253 kilometers (160 miles) for the object's diameter with an albedo of 0.08 and an absolute magnitude of 6.3.[6]

References[]

  1. ^ Jump up to: a b "432949 (2012 HH2)". Minor Planet Center. Retrieved 19 July 2021.
  2. ^ Jump up to: a b c d e "JPL Small-Body Database Browser: 432949 (2012 HH2)" (2021-06-06 last obs.). Jet Propulsion Laboratory. Retrieved 19 July 2021.
  3. ^ Jump up to: a b c d e f Johnston, Wm. Robert (18 August 2020). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 19 July 2021.
  4. ^ Jump up to: a b "Orbit Fit and Astrometric record for 432949 (Type: 5:4E)". Southwest Research Institute. Retrieved 5 January 2019.The Deep Ecliptic Survey Object Classifications
  5. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 July 2021.
  6. ^ Brown, Michael E. "How many dwarf planets are there in the outer solar system?". California Institute of Technology. Retrieved 19 July 2021.

External links[]

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