(119979) 2002 WC ₁₉

Asteroid (119979) 2002 WC 19th
Properties of the orbit ( animation ) Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type	RKBO 1: 2  ( Twotino ), "Distant Object"
Major semi-axis	47,562  AU
eccentricity	0.26
Perihelion - aphelion	35.22 AU - 59.905 AU
Inclination of the orbit plane	9.2 °
Length of the ascending node	109.7 °
Argument of the periapsis	45.6 °
Time of passage of the perihelion	May 8, 2057
Sidereal period	328 a 0.2 M
Mean orbital velocity	4.306 km / s
Physical Properties
Medium diameter	525 km
Albedo	0.07-0.09
Absolute brightness	5.2 ± 0.5 mag
Spectral class	C B-V = 0.00 ± 0.00 V-R = 0.65 ± 0.01
history
Explorer	Chadwick A. Trujillo Michael E. Brown Eleanor F. Helin Steven H. Pravdo Kenneth J. Lawrence Michael Hicks
Date of discovery	November 16, 2002
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.

(119979) 2002 WC ₁₉ is a large trans-Neptunian object , which is classified as a resonant KBO ( Twotino ) or more generally as a distant object . Because of its size, the asteroid is a dwarf planet candidate . It has a moon that is about a quarter the diameter of the parent asteroid.

discovery

2002 WC ₁₉ was discovered on November 16, 2002 by a team of astronomers consisting of Chad Trujillo , Mike Brown , Eleanor "Glo" Helin , Steven Pravdo, Kenneth Lawrence and Michael Hicks as part of Near Earth Asteroid Tracking at the Palomar Observatory . The discovery was announced on January 5, 2003 along with the 2002 XV ₉₃ and 2002 XW ₉₃ ; the planetoid was given the minor planet number 119979 by the IAU on November 16, 2005 .

After its discovery, WC _{19 could be identified} in photos up to December 16, 2001, which were also taken at the Palomar Observatory, and thus its observation period was extended by exactly 11 months in order to calculate its orbit more precisely. In February 2018, a total of 113 observations were made over a period of 17 years. The last observation so far was made in December 2017 at the Mauna Kea Observatory . (As of February 8, 2019)

properties

The orbit of 2002 WC ₁₉ (blue) compared to Pluto and the giant planets.

Neptune is kept stationary at 5 o'clock.

Orbit

2002 WC ₁₉ orbits the sun in 328.02 years in an elliptical orbit between 35.22  AU and 59.91 AU from its center. The orbit eccentricity is 0.260, the orbit is 9.20 ° inclined to the ecliptic . The planetoid is currently 40.30 AU from the sun and 39.69 AU from earth . He will next pass perihelion in 2057, so the last perihelion should have occurred in 1729.

Both Marc Buie ( DES ) and the Minor Planet Center classify the asteroid as Twotino (RKBO 1: 2), the latter also generally as a distant object

size

A diameter of around 525 km is currently assumed, based on a reflectivity of 10.7% and an absolute brightness of 4.7  ^m . Based on this diameter, the total area is about 866,000 km². The apparent brightness of 2002 WC ₁₉ is 21.03  ^m . The mean surface temperature is estimated at 40 K (-233 ° C ) based on the sun distance .

Since it can be assumed that 2002 WC ₁₉ 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 2002 WC ₁₉ to potentially is a dwarf planet.

Provisions of the diameter for 2002 WC ₁₉

year	Dimensions km	source
2013	348.0 ± 45.0	Lellouch u. a.
2013	482.53	LightCurve DataBase
2015	540.0 (system) 525.0	Grundy et al. a.
2018	490.0	Brown
The most precise determination is marked in bold .

moon

→ Main article : S / 2007 (119979) 1

On February 27, 2007, a team of astronomers led by Keith S. Noll announced the discovery of a moon around 126 km in diameter, which was tracked using images from the Hubble Space Telescope . It orbits in 2002 WC ₁₉ , the common center of mass in 5.5 days km at an average distance of 5720 ± 90th So far, no mass determination has been carried out.

The 2002 WC ₁₉ system at a glance:

Components	Physical parameters			Path parameters				discovery
Surname	Throughput diameter (km)	Relative size %	Mass (kg)	Major semi-axis (km)	Orbital time (d)	eccentricity	Inclination to the 2002 WC 19 equator	Date of discovery Date of publication
(119979) 2002 WC 19	525.0	100.0	?	-	-	-	-	November 16, 2002 November 16, 2005
S / 2007 (119979) 1	126.0	24.0	?	4090	8.403	0.2	?	November 5, 2006 February 27, 2007

See also

• List of trans-Neptunian objects
• List of dwarf planets of the solar system
• List of asteroids
• List of moons from asteroids

Web links

• How many dwarf planets are there in the outer solar system? Current list of the largest TNOs from Mike Brown
• Free the dwarf planets! Mike Brown's column on the IAU and the dwarf planets regarding their classifications (23 August 2011)

Individual evidence

1. ^ ^{A b} Marc W. Buie : Orbit Fit and Astrometric record for 119979 . SwRI (Space Science Department). Retrieved February 8, 2019.
2. ↑ ^{a b} MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Retrieved February 8, 2019.
3. ↑ ^{a b} W. Grundy: Orbit Status of Known Binary TNOs . Lowell Observatory . Retrieved February 8, 2019.
4. ↑ ^{a b c} (119979) 2002 WC19 at the IAU Minor Planet Center (English) Retrieved on February 8, 2019.
5. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
6. ↑ ^{a b} LCDB Data for 2002 WC19 . MinorPlanetInfo. May 2013. Retrieved February 8, 2019.
7. ^ W. Grundy: 119979 (2002 WC19) . Lowell Observatory . September 14, 2014. Retrieved February 8, 2019.
8. ^ Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved February 8, 2019.
9. ↑ MPC : MPEC 2003-A25: 2002 WC19, 2002 XV93, 2002 XW93 . IAU . January 5, 2003. Retrieved February 8, 2019.
10. ↑ (119979) 2002 WC19 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved February 8, 2019.
11. ↑ (119979) 2002 WC19 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 February 8, 2019.
13. ↑ E. Lellouch et al. a .: “TNOs are Cool”: A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations (PDF) . In: Astronomy and Astrophysics . 557, No. A60, June 10, 2013, p. 19. bibcode : 2013A & A ... 557A..60L . doi : 10.1051 / 0004-6361 / 201322047 .
14. ↑ W. Grundy: TNBS with known P, a, and e . Lowell Observatory . September 14, 2014. Retrieved February 8, 2019.