(471165) 2010 HE 79

from Wikipedia, the free encyclopedia
Asteroid
(471165) 2010 HE 79
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type SDO / Centaur ,
"Distant Object"
Major semi-axis 39.229  AU
eccentricity 0.181
Perihelion - aphelion 32.14 AU - 46.318 AU
Inclination of the orbit plane 15.7 °
Length of the ascending node 238.7 °
Argument of the periapsis 284.2 °
Time of passage of the perihelion 17th November 1975
Sidereal period 245 a 8.5 M
Mean orbital velocity 4.717 km / s
Physical Properties
Medium diameter approx. 447 km
Albedo 0.06-0.10
Rotation period 19.49 ± 0.05 h (0.812) d
Absolute brightness 5.01 ± 0.04 - 5.5 mag
Spectral class C.
history
Explorer Scott S. Sheppard
Radosław Poleski
Andrzej Udalski
Chadwick A. Trujillo
Date of discovery April 21, 2010
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.

(471165) 2010 HE 79 is a large trans-Neptunian object in the Kuiper belt , which is classified as SDO and centaur in terms of orbital dynamics . Because of its size, the asteroid is a dwarf planet candidate .

discovery

2010 HE 79 was discovered on April 21, 2010 by a team of astronomers consisting of Scott Sheppard , Radosław Poleski, Andrzej Udalski and Chad Trujillo at the Las Campanas Observatory ( Chile ). The discovery was made within the framework of the OGLE-IV program at Warsaw University . The discovery was announced on May 10, 2011, and the IAU gave the planetoid minor planet number 471165 .

After its discovery, HE 79 could be identified in photos up to May 24, 1992, taken as part of the Digitized Sky Survey program at the Siding Spring Observatory ( Australia ), and its observation period was extended by 18 years in order to calculate its orbit more precisely. In April 2017, a total of 179 observations over a period of 24 years were available. The last observation so far was carried out in July 2015 Pan-STARRS telescope (PS1). (As of March 3, 2019)

properties

Orbit

2010 HE 79 orbits the sun in 245.71 years on a slightly elliptical orbit between 32.14  AU and 46.32 AU from its center. The orbit eccentricity is 0.181, the orbit is inclined 15.67 ° to the ecliptic . The planetoid is currently 37.20 AU from the Sun. He last passed through perihelion in 1975, so the next perihelion should take place in 2221.

Both Marc Buie ( DES ) and the Minor Planet Center classify the planetoid as SDO and as centaurs ; the latter also generally lists it as a “distant object” . The Johnston's Archives, however, classify it as a possible Plutino .

Size and rotation

A diameter of 447 km is currently assumed, based on a reflectivity of 6% and an absolute brightness of 5.5  m . Assuming a diameter of 447 km, this results in a total surface of about 628,000 km 2 . The apparent brightness of 2010 HE 79 is 21.17  m , the mean surface temperature is estimated at 44 K (−229 ° C) based on the distance from the sun  .

Since it can be assumed that 2010 HE 79 is in hydrostatic equilibrium due to its size and must therefore be largely round, it should meet the criteria for classification as a dwarf planet . Mike Brown expects that it is at 2010 HE 79 to possibly is a dwarf planet.

Using light curve observations , the 2010 HE 79 rotates once around its axis in 19 hours and 29.4 minutes. This means that in a 2010 HE 79 year it performs 110 511.4 self- rotations (“days”). However, this is still fraught with uncertainties, as the observation time at that time was insufficient and the error rate is around 30%.

Provisions of the diameter for 2010 HE 79
year Dimensions km source
2013 401.35 LightCurve DataBase
2018 423.0 Johnston
2018 447.0 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 471165 . SwRI (Space Science Department). Retrieved March 3, 2019.
  2. ↑ a b MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 3, 2019.
  3. ↑ a b c (471165) 2010 HE79 at the IAU Minor Planet Center (English) Retrieved March 3, 2019.
  4. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  5. ↑ a b S. Benecchi, S. Sheppard : Light Curves of 32 Large Transneptunian Objects (PDF) . In: The Astronomical Journal . 145, No. 5, January 24, 2013, p. 124, 19. arxiv : 1301.5791 . bibcode : 2013AJ .... 145..124B . doi : 10.1088 / 0004-6256 / 145/5/124 .
  6. ↑ a b LCDB Data for (471165) 2010HE79 . MinorPlanetInfo. 2013. Retrieved March 3, 2019.
  7. ↑ MPC : MPEC 2011-J43: 2010 HE79 . IAU . May 10, 2011. Retrieved March 3, 2019.
  8. ↑ (471165) 2010 HE79 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 3, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  9. ↑ MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Retrieved March 3, 2019.
  10. ^ A b Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 3, 2019.
  11. ↑ (471165) 2010 HE79 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  12. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 3, 2019.