(432949) 2012 HH2
![]() Discovery animation by the Astronomical Research Institute of 2012 HH2 | |
Discovery[1] | |
---|---|
Discovered by | T. Vorobjov |
Discovery site | Astronomical Research Institute (H21) |
Discovery date | 19 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 arc | 19.16 yr (6,998 d) |
Aphelion | 40.414 AU |
Perihelion | 29.201 AU |
34.808 AU | |
Eccentricity | 0.1611 |
205.36 yr (75,008 d) | |
40.568° | |
0° 0m 17.28s / day | |
Inclination | 28.585° |
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[]
- ^ Jump up to: a b "432949 (2012 HH2)". Minor Planet Center. Retrieved 19 July 2021.
- ^ 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.
- ^ 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.
- ^ 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
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 July 2021.
- ^ Brown, Michael E. "How many dwarf planets are there in the outer solar system?". California Institute of Technology. Retrieved 19 July 2021.
External links[]
- MPEC 2012-H36 : DAILY ORBIT UPDATE (2012 APR. 21 UT) (Discovery mention on Daily Orbit Update)
- MPEC 2012-L20 : 2012 HH2 (Revision to MPEC 2012-J31)
- Home page of the Astronomical Research Institute
- (432949) 2012 HH2 at the JPL Small-Body Database
- Minor planet object articles (numbered)
- 4:5 resonance
- Discoveries by Tomáš Vorobjov
- Astronomical objects discovered in 2012