(10199) Chariklo

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Asteroid
(10199) Chariklo
Properties of the orbit ( animation )
Epoch:  4th September 2017 ( JD 2,458,000.5)
Orbit type centaur
Major semi-axis 15.822  AU
eccentricity 0.172
Perihelion - aphelion 13,099 AU - 18,544 AU
Inclination of the orbit plane 23.4 °
Length of the ascending node 300.4 °
Argument of the periapsis 242.9 °
Time of passage of the perihelion February 5, 2004
Sidereal period 62 a 11 M
Mean orbital velocity 7.442 km / s
Physical Properties
Medium diameter 248 ± 18 km
Albedo 0.045 ± 0.01
Rotation period 7 h 15 s
Absolute brightness 6.6 likes
Spectral class
(according to SMASSII) 		D.
history
Explorer Spacewatch
Date of discovery February 15, 1997
Another name 1997 CU 26
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.

(10199) Chariklo is the largest asteroid belonging to the centaur group . The equivalent diameter is 248 km.

Discovery and naming

Chariklo was on 15 February 1997 by James V. Scotti from Space Watch project at the Observatory of Kitt Peak discovered. The provisional designation was 1997 CU 26 . It is named after the nymph Chariklo , the wife of the centaur Chiron . After her discovery, Chariklo found herself on older recordings from 1988. In July 2017, 577 recordings were available over a period of 27 years, so that their orbit parameters are known relatively precisely.

Track properties

Chariklo moves in an elliptical orbit ( eccentricity = 0.172), the period of which is 62 years and 11 months. The mean distance from the Sun is 15.8  AU . She last experienced her perihelion at the turn of the year 2003/2004. It is currently about 15.7 AU from the Sun. Presumably it comes from the Kuiper Belt.

Physical Properties

Investigations in 2013 with the Herschel space telescope (instruments SPIRE and PACS) combined with the revised data of the Spitzer space telescope (instrument MIPS) and those of the WISE come to the conclusion that the diameter of Chariklo is around 248 km. On the occasion of a star occlusion, the diameter could be determined to be 253.8 km. Should Chariklo consist mainly of ice, it could be in hydrostatic equilibrium and thus largely round.

Rings and Hypothetical Moons

Artist's impression

Chariklo is surrounded by two rings of water ice , the 7 km wide inner ice ring has a radius of 391 km and the 3 km wide outer ice ring has a radius of 405 km. The reason for the existence and stability of the ring system is so far unknown. Both rings are separated from each other by a gap about 9 km wide. For this reason, among other things, it is assumed that at least one shepherd's moon still exists, which stabilizes the ring system. The escape speed from Chariklo should be around 350 km / h.

Chariklo was the first asteroid to find rings. The discovery of the ring system was a result of the evaluation of a star eclipse on June 3, 2013. Rings of Chiron and Haumea have now also been observed using the same method . The position of Chariklos' rings explains the temporary eclipse around 2008 and the simultaneous disappearance of the water ice spectra. In 2008 the view from the earth fell on the edge of the ring system, which contains the bright ice crystals.

A Japanese research team modeled a realistic simulation of the two rings around Chariklo. It turned out that the inner ring should be unstable without the presence of a shepherd's moon, as it would have to disintegrate within less than 100 years due to its own gravity. An alternative explanation for its stability would be a composition of particles only a few millimeters in size.

See also

literature

  • Jan Hattenbach: Minor planet Chariklo has rings. In: Stars and Space. ISSN  0039-1263 , edition 6/2014, pp. 18-20. ( Excerpt on the internet )
  • F. Braga-Ribas, B. Sicardy, JL Ortiz, C. Snodgrass, F. Roques, R. Vieira-Martins, JIB Camargo, M. Assafin, R. Duffard, E. Jehin: A ring system detected around the Centaur ( 10199) Chariklo . In: Nature . tape 508 , no. 7494 . Nature Research, 2014, p. 72-75 .

Individual evidence

  1. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  2. ↑ a b S. Fornasier, E. Lellouch, T. Müller, P. Santos-Sanz, P. Panuzzo, C. Kiss, T. Lim, M. Mommert, D. Bockelée-Morvan, E. Vilenius, J. Stansberry , GP Tozzi, S. Mottola, A. Delsanti, J. Crovisier, R. Duffard, F. Henry, P. Lacerda, A. Barucci, A. Gicquel: TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70 to 500 μ m . In: Astronomy and Astrophysics . 555, No. A15, 2013, p. 22. arxiv : 1305.0449v2 . bibcode : 2013A & A ... 555A..15F . doi : 10.1051 / 0004-6361 / 201321329 .
  3. ↑ (10199) Chariklo in the Small-Body Database of the Jet Propulsion Laboratory (English).Template: JPL Small-Body Database Browser / Maintenance / Alt
  4. ↑ (10199) Chariklo in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  5. ↑ R. Leiva, B. Sicardy, B. Camargo, JL. Ortiz, et al .: Size and shape of Chariklo from multi-epoch stellar occultations . In: AJ . 2017. arxiv : 1708.08934 . doi : 10.3847 / 1538-3881 / aa8956 .
  6. ↑ a b c F. Braga-Ribas, B. Sicardy, JL Ortiz, et al .: A ring system detected around the Centaur (10199) Chariklo . In: Nature . 508, 2014, pp. 72-75. arxiv : 1409.7259 . doi : 10.1038 / nature13155 .
  7. ↑ The first ring system around an asteroid. Discovered two rings around Chariklo . Translation of ESO press release eso1410 March 26, 2014 On: eso.org ; last accessed on March 29, 2014.
  8. ↑ JL Ortiz, R. Duffard, N. Pinilla-Alonso, A. Alvarez-Candal, P. Santos-Sanz, N. Morales, E. Fernández-Valenzuela, J. Licandro, A. Campo Bagatin, A. Thirouin: Possible ring material around centaur (2060) Chiron . In: Astronomy & Astrophysics . 576, 2015, p. A18. arxiv : 1501.05911 . doi : 10.1051 / 0004-6361 / 201424461 .
  9. ↑ JL Ortiz, P. Santos-Sanz, B. Sicardy, G. Benedetti-Rossi, D. Bérard, N. Morales, R. Duffard, F. Braga-Ribas, U. Hopp, C. Ries, V. Nascimbeni, F. Marzari, V. Granata, A. Pál, C. Kiss, T. Pribulla, R. Komžík, K. Hornoch, P. Pravec, P. Bacci, M. Maestripieri, L. Nerli, L. Mazzei, M. Bachini, F. Martinelli et al .: The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation . In: Nature . 550, October 12, 2017, pp. 219-223. doi : 10.1038 / nature24051 .
  10. ↑ Shugo Michikoshi, Eiichiro Kokubo: First Global Simulation Yields New Insights into Ring System. Center for Computational Astrophysics, NAOJ, April 28, 2017, accessed September 17, 2017 .