(523659) 2012 HG 84

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Asteroid
(523659) 2012 HG 84
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type CKBO ( "Hot" )
"Distant Object"
Major semi-axis 43,385  AU
eccentricity 0.094
Perihelion - aphelion 39,319 AU - 47,451 AU
Inclination of the orbit plane 10.8 °
Length of the ascending node 266.5 °
Argument of the periapsis 22.2 °
Time of passage of the perihelion August 26, 2048
Sidereal period 285 a 9.2 M
Mean orbital velocity 4.485 km / s
Physical Properties
Medium diameter approx. 358 km
Albedo 0.08-0.09
Absolute brightness 5.4 - 5.7 mag
history
Explorer Megan E. Schwamb
Pan-STARRS
Date of discovery April 17, 2012
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(523659) 2012 HG 84 is a large trans-Neptunian object in the Kuiper belt , which is classified as Cubewano (CKBO) in terms of railway dynamics . Due to its size, the asteroid may be one of the dwarf planet candidates .

discovery

2012 HG 84 was discovered on April 17, 2012 by Meg Schwamb at the La Silla Observatory ( Chile ) of the European Southern Observatory (ESO). The discovery was announced on July 15, 2016 by a team of astronomers consisting of B. Gibson, T. Goggia, N. Primak, A. Schultz and M. Willman ( Pan-STARRS ) of the Haleakalā Observatory ( Maui ), who received the planetoid on September 25, 2018 from the IAU the minor planet number 523659 .

After its discovery, HG 84 could be identified in photos up to April 20, 2010, taken as part of the Pan-STARRS program, and its observation period was extended by two years in order to calculate its orbit more precisely. Since then, the planetoid has been observed through various earth-based telescopes. In October 2018, there were a total of 126 observations over a period of 8 years. The last observation so far was carried out again at the Pan-STARRS telescope (PS1) in June 2017. (As of March 18, 2019)

properties

Orbit

2012 HG 84 orbits the sun in 285.77 years on a slightly elliptical orbit between 39.32  AU and 47.45 AU from its center. The orbital eccentricity is 0.094, the orbit is 10.85 ° inclined to the ecliptic . The planetoid is currently 40.30 AU from the sun. He will next pass perihelion in 2048, so the last perihelion should have occurred in 1762.

Marc Buie ( DES ) classifies the asteroid as Cubewano , whereby it belongs to the orbital dynamics “hot” classical KBO , while the Minor Planet Center does not have a specific classification; the latter classifies it as a non-SDO and generally as a “distant object” .

size

A diameter of 358 km is currently assumed, based on a reflectivity of 8% and an absolute brightness of 5.7  m . Based on this diameter, the total area is about 403,000 km². The apparent magnitude of 2012 HG 84 is 21.76  m .

Since it is conceivable that 2012 HG 84 is in hydrostatic equilibrium due to its size and could therefore be largely round, it may meet the criteria for classification as a dwarf planet . Mike Brown expects that it is at 2012 HG 84 to perhaps is a dwarf planet.

Provisions of the diameter for 2012 HG 84
year Dimensions km source
2018 368.0 Johnston
2018 358.0 Brown
The most precise determination is marked in bold .

See also

Web links

Individual evidence

  1. ^ A b Marc W. Buie : Orbit Fit and Astrometric record for 523659 . SwRI (Space Science Department). Retrieved March 18, 2019.
  2. ↑ a b c Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 18, 2019.
  3. ↑ a b c (523659) 2012 HG84 at the IAU Minor Planet Center (English) Retrieved March 18, 2019.
  4. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  5. ↑ MPC : MPEC 2016-N104: 2012 HG84 . IAU . July 15, 2016. Retrieved March 18, 2019.
  6. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 18, 2019.
  7. ↑ (523659) 2012 HG84 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 18, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  8. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 18, 2019.
  9. ↑ (523659) 2012 HG84 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  10. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 18, 2019.