(19521) Chaos

Asteroid (19521) Chaos
Properties of the orbit ( animation ) Epoch: April 27, 2019 ( JD 2,458,600.5)
Orbit type	Cubewano
Major semi-axis	45.458 AU
eccentricity	0.099
Perihelion - aphelion	40.974 AU - 49.942 AU
Inclination of the orbit plane	12.1 °
Length of the ascending node	50 °
Argument of the periapsis	58.5 °
Time of passage of the perihelion	September 30, 2035
Sidereal period	306 a 6 M
Mean orbital velocity	4.403 km / s
Physical Properties
Medium diameter	${\ displaystyle 600 _ {- 130} ^ {+ 140} \ mathrm {km}}$
Albedo	${\ displaystyle 0 {,} 050 _ {- 0.016} ^ {+ 0.030} \ mathrm {}}$
Absolute brightness	4.8 likes
history
Explorer	Deep Ecliptic Survey
Date of discovery	November 19, 1998
Another name	1998 WH ₂₄
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.

(19521) Chaos is a large trans-Neptunian object in the Kuiper Belt that is classified as a Cubewano . Due to its size of an estimated 600 km, it is a dwarf planet candidate .

Discovery and naming

Chaos was discovered on November 19, 1998 by the Deep Ecliptic Survey team of astronomers at Kitt Peak National Observatory in Arizona . The provisional designation was 1998 WH ₂₄ . After the orbit had been determined with sufficient accuracy, the IAU gave it the minor planet number 19521 .

After its discovery, chaos could be identified in photos from October 17, 1991, and thus its orbit calculated more precisely. Since then, the asteroid has been observed through various telescopes such as the Herschel Space Telescope and Earth-based telescopes. In February 2018, a total of 112 observations were made during 12 oppositions over a period of 26 years.

On March 28, 2002, the Minor Planet Center announced the name Chaos .

properties

Orbit of Chaos (white) compared to that of Neptune (blue), Pluto (purple), and others.

Orbit

Chaos revolves around the sun on a slightly elliptical orbit - the orbital eccentricity is 0.10 - at an average distance of 45.45 AU from its center. The period of circulation is 306.50 years. He will pass perihelion for the next time in 2035. It is currently about 41.3 AU from the Sun. The orbit is inclined 12.1 ° to the ecliptic . It is classified as Cubewano by both the MPC and Marc Buie ( DES ). Thanks to its perihelion, which is about 41 AU from the Sun, chaos is not subject to any significant orbital disturbances by Neptune . Since there are only observational data from 12 oppositions in 26 years, the orbit elements are subject to corresponding uncertainties.

size

Investigations with the Herschel space telescope (instrument PACS) in combination with older data from the Spitzer space telescope (instrument MIPS) determined the chaos' albedo to be 0.05, from which, with known brightness, an equivalent diameter of 600 km can be concluded.

Size comparison with Pluto

.

Provisions of the diameter for chaos
year	Dimensions km	source
2004	<742.0	Altenhoff et al. a.
2005	<747.0	Grundy et al. a.
2005	600.0 ^+140.0_−130.0	Vilenius et al. a.
2018	612.0	Brown
The most precise determination is marked in bold .

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

↑ v ≈ π * a / period (1 + sqrt (1-e²))
↑ ^a ^b ^c ^d E. Vilenius, C. Kiss, M. Mommert, T. Müller, P. Santos-Sanz, A. Pal, J. Stansberry, M. Mueller, N. Peixinho, S. Fornasier, E. Lellouch , A. Delsanti, A. Thirouin, JL Ortiz, R. Duffard, D. Perna, N. Szalai, S. Protopapa, F. Henry, D. Hestroffer et al .: “TNOs are Cool”: A survey of the trans -Neptunian region. VI. Herschel / PACS observations and thermal modeling of 19 classical Kuiper belt objects . In: Astronomy and Astrophysics . 541, No. A94, May 4, 2012, p. 17. arxiv : 1204.0697 . doi : 10.1051 / 0004-6361 / 201118743 .
↑ (19521) Chaos in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved February 17, 2018.
↑ ^a ^b (19521) Chaos at the IAU Minor Planet Center (English) Retrieved on February 17, 2018.
↑ MPC / MPO / MPS archives . Minor Planet Center. Retrieved December 19, 2017.
↑ AstDyS-2. Universita di Pisa, accessed February 17, 2018 .
↑ Brian G. Marsden: MPEC 2009-P26: Distant Minor Planets (2009 Aug. 17.0 TT.) . In: IAU Minor Planet Center . August 7, 2009. Retrieved December 19, 2017.
^ Marc W. Buie: Orbit Fit and Astrometric record for 19521 . SwRI (Space Science Department). Retrieved February 17, 2018.
↑ W. Altenhoff u. a .: Size estimates of some optically bright KBOs (February 2004)
↑ W. Grundy et al. a .: Diverse albedos of small trans-neptunian objects (February 2005)
↑ M. Brown : How many dwarf planets are there in the outer solar system? (November 2018)

[MittOrbGesch-1] v ≈ π * a / period (1 + sqrt (1-e²))

[TNOsCool6-2] E. Vilenius, C. Kiss, M. Mommert, T. Müller, P. Santos-Sanz, A. Pal, J. Stansberry, M. Mueller, N. Peixinho, S. Fornasier, E. Lellouch , A. Delsanti, A. Thirouin, JL Ortiz, R. Duffard, D. Perna, N. Szalai, S. Protopapa, F. Henry, D. Hestroffer et al .: “TNOs are Cool”: A survey of the trans -Neptunian region. VI. Herschel / PACS observations and thermal modeling of 19 classical Kuiper belt objects . In: Astronomy and Astrophysics . 541, No. A94, May 4, 2012, p. 17. arxiv : 1204.0697 . doi : 10.1051 / 0004-6361 / 201118743 .

[jpl-3] (19521) Chaos in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved February 17, 2018.

[MPC-4] (19521) Chaos at the IAU Minor Planet Center (English) Retrieved on February 17, 2018.

[MPC-Circulars-Archive-5] MPC / MPO / MPS archives . Minor Planet Center. Retrieved December 19, 2017.

[AstDyS-6] AstDyS-2. Universita di Pisa, accessed February 17, 2018 .

[K09P26-7] Brian G. Marsden: MPEC 2009-P26: Distant Minor Planets (2009 Aug. 17.0 TT.) . In: IAU Minor Planet Center . August 7, 2009. Retrieved December 19, 2017.

[BuieOrbit-8] Marc W. Buie: Orbit Fit and Astrometric record for 19521 . SwRI (Space Science Department). Retrieved February 17, 2018.

[9] W. Altenhoff u. a .: Size estimates of some optically bright KBOs (February 2004)

[10] W. Grundy et al. a .: Diverse albedos of small trans-neptunian objects (February 2005)

[11] M. Brown : How many dwarf planets are there in the outer solar system? (November 2018)