(136108) Haumea

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Dwarf planet
(136108) Haumea
Haumea Hubble.png
Haumea with the moons Hiʻiaka (above) and Namaka (below) through the Hubble Space Telescope (2015).
Properties of the orbit
( animation )
Major semi-axis 43,287  AU
(6,475.6 million km)
Perihelion - aphelion 34.97-51.60 AU
eccentricity 0.192
Inclination of the orbit plane 28.21 °
Sidereal period 284 a 9 M 17 d
Mean orbital velocity 4.485 km / s
Physical Properties
Equatorial diameter * 2100 × 1680 km
Pole diameter * 1070 km
Dimensions 4.01 ± 0.04 x 10 21  kg
Medium density approx. 2 g / cm 3
Gravitational acceleration * ≈ 0.401 m / s 2
Escape speed ≈ 0.809 km / s
Rotation period 3 h 55 m
Geometric albedo 0.51 ± 0.02
Max. Apparent brightness 17.3 m
Temperature *
min. - average - max.
<50 K
* based on the zero level of the dwarf planet
Others
Moons 2
Explorer JL Ortiz ,
FJ Aceituno ,
P. Santos Sanz or
M. Brown ,
C. Trujillo ,
D. Rabinowitz
Date of discovery March 7, 2003
EightTNOs.png
Size comparison of the 10 largest TNOs

(136108) Haumea (former, provisional designation 2003 EL 61 ) is a dwarf planet of the subclass of the Plutoids and is one of the largest known objects in the Kuiper Belt . On the one hand it was first classified as Cubewano , on the other hand it was later seen in a possible 7:12 response with Neptune. Because of its rapid rotation , it has a strongly ellipsoidal shape with an equatorial diameter of about 2300 km and a distance between the poles of only about 1100 km . As part of the observations of a star eclipse on January 21, 2017, it was discovered that Haumea has a ring .

Discovery and naming

The discovery of Haumea was announced on July 28th, 2005 by JL Ortiz , FJ Aceituno and P. Santos Sanz from the Sierra Nevada Observatory in Spain after re-evaluation of recordings from March 7th, 2003 after the working group of Mike Brown on July 20th, 2005 at Caltech in the USA had announced a conference contribution about the property under the working name K40506A. Ortiz's observations were made with a commercially available Schmidt-Cassegrain telescope with a primary mirror 35 cm in diameter, as is also used by amateur astronomers . The group was initially only able to track the object for three days . The object was later found on archival recordings, including images from the Palomar Observatory Sky Survey from 1955. Based on this additional data, a reliable orbit determination was possible, so that the discovery was announced on July 28, 2005.

Because of the unexplained doubts that were caused by the fact that the Ortiz group had downloaded and evaluated the observation data of the group led by Mike Brown from the Internet before the reported discovery, without indicating, the Minor Planet Center has deleted the names of the discoverers from its list and instead lists the Sierra Nevada Observatory.

Since then, Haumea has been observed through various space and earth-based telescopes; In June 2018, there were 1660 observations on 24 oppositions over a period of 63 years.

Discovery controversy

Mike Brown , Chad Trujillo and David Rabinowitz of the California Institute of Technology found the object on December 28, 2004 with the help of the Palomar Observatory . Mike Brown's working group used the unofficial working name "Santa" for the object. Because of the publication of the discovery of Haumea (ex. 2003 EL 61 ) by the Spanish astronomers , Brown's group announced the discovery of the two even larger trans-Neptunian objects (136199) Eris (ex. 2003 UB 313 , Xena) and (136472) Makemake ( ex. 2005 FY 9 ) only a few hours later at a press conference.

Brown and his group first recognized Ortiz et al. as the first discoverer from Haumea until it was found that Ortiz et al. had accessed publicly available telescope logs of Brown's group on the Internet before Ortiz's group made the discovery known. While the allegation was in the room that the Spanish group had only found the object with the help of these data on their photos from 2003, Ortiz assured that they had only checked whether the object announced under the working name K40506A by Brown et al. was about the same celestial body that his group had found independently. Brown's group then accused Ortiz's group of violating the rules of scientific ethics and demanded that the Minor Planet Center (MPC), Ortiz et al. to revoke the status of the first discoverer.

The controversy stems from the fact that according to the valid rules of the International Astronomical Union, the discovery of an asteroid or dwarf planet is assigned to those observers who are the first to transmit sufficient position measurements to the MPC with which the orbit of the object in the solar system can be determined with sufficient accuracy. Brown's group found Haumea at the end of 2004, but kept the discovery a secret. Ortiz's group, however, submitted its observations to the MPC on July 28, 2005. The MPC therefore cites the Sierra Nevada Observatory as an explorer.

Surname

On September 17, 2008, EL 61 was named after the Hawaiian goddess Haumea by the International Astronomical Union, following a proposal by Brown . At the same time, Haumea was recognized as the fifth dwarf planet of the solar system and thus also as the fourth plutoid. Ortiz's suggested name was Ataecina , after the name of a deity worshiped on the Iberian Peninsula in pre-Roman times.

Unlike Pluto or Ceres , Haumea, like most dwarf planets, has no official astronomical symbol or one that is commonly used. Haumea symbols circulating on the Internet (e.g. Haumea proposal symbol.pngor Haumea symbol.svg) are designs by private individuals. An official recognition or use is not foreseeable, since astronomical symbols only play a subordinate role in modern astronomy.

The orbit of (136108) Haumea (green) compared to that of (134340) Pluto (red), (136472) Makemake (blue) and Neptune (gray); Object sizes not to scale

properties

Orbit

Haumea orbits the Sun in an elliptical orbit in approximately 285 years and 5 months . The perihelion is about 35  AU from the Sun, the aphelion about 51½ AU. It passes through its perihelion again in the spring of 2133. It is currently about 50.5 AU from the Sun. The orbital plane is about 28.2 ° inclined to the ecliptic .

Size and rotation

From the orbital motion of the larger of the two moons Hi'iaka (see below), the mass of Haumea was able to be 006 ± 0.040 with great accuracye21  kg can be determined, which corresponds to 30 percent of the mass of Pluto. Hi'iaka's mass was 79 ± 0.11e19  kg calculated. The observed light curve shows that Haumea rotates around its own axis in only 3: 54: 55.2 hours - and therefore faster than any other known object in the solar system with a size above 100 km. The shape of a three-axis Jacobi ellipsoid with axes of 1920 km × 1540 km × 990 kmcan also be deduced from the light curve. Haumea has been confirmed as a dwarf planet, as it is very likely to be in hydrostatic equilibrium , despite its shape, which differs widely from the spherical shape.

In January 2017 a star occultation occurred , which resulted in significantly higher values. The investigations showed proportions of 2322 × 1704 × 1138 km ( geometric mean 1595 ± 11 km), which at least in relation to the proportions confirmed the earlier results, but Haumea accordingly has a diameter on its longitudinal axis that corresponds to the diameter of Eris in particular (2326 km ) and also resembles Pluto . This makes Haumea significantly larger than previously assumed. The mean value of 1595 km is above the values ​​of Gonggong (1535 km) and Makemake (1430 km), which makes Haumea the third largest dwarf planet at the moment. The result of the investigations is also an average density of 1.885 g / cm³, which more closely matches the average densities of other large TNOs.

Simulation of Haumea's rotation
Provisions of the diameter for Haumea
year Dimensions km source
2005 1379.0 ± 57.0
(1960 × 1518 × 996)
Rabinowitz et al. a.
2006 1450.0 Lacerda et al. a.
2007 1150.0 +250.0−100.0 (System) Stansberry et al. a.
2009 1380 Ragozzine et al. a.
2010 1150.0 Tancredi
2010 1324.0 ±
167.0 1438.0
Lellouch u. a.
2013 1239.5 +68.7−57.8 (System) Fornasier et al. a.
2013 1345.0 (system) Mommert et al. a.
2014 1430.0
(1920 × 1540 × 990)
Lockwood et al. a.
2017 1595.0 ± 11.0
(2322 × 1704 × 1138)
Ortiz et al. a.
2018 1252.0 Brown et al. a.
2019 2100 × 1680 × 1070 Dunham et al. a.
The most precise determination is marked in bold .

The rapid rotation of Haumea is explained by its formation through the collision of two dwarf planets. Accordingly, the original celestial body should have collided with an object about 1000 km in size. A large part of the ice mantle was blown away by the collision, which is why Haumea has a significantly higher density than other objects in the Kuiper Belt. From the fragments of the collision, not only the two moons emerged, but also other smaller objects that together with Haumea form a family of celestial bodies. In addition to Haumea and its moons, confirmed members of the Haumea family are: 2002 TX 300 , 2003 OP 32 , 2005 RR 43 , 2009 YE 7 , 1995 SM 55 , 2005 CB 79 , 1996 TO 66 , 2003 UZ 117 , 2003 SQ 317 and 1999 OY 3 .

surface

Spectroscopic observations at the Keck and Gemini observatories show strong traces of crystalline water ice on the surface of Haumea. This only forms from 110 K, while Haumea's surface temperature is less than 50 K. Since the lifespan of crystalline ice due to cosmic rays is on the order of 10 million years, it is believed that Haumea's surface was only recently covered with fresh water ice. Volatile substances like methane were apparently lost in the aforementioned collision; in contrast to Makemake, the spectral analysis shows no methane.

The apparent brightness is 17.3 m during opposition .

Moons and ring

Artist's impression of Haumea with her moons
Simulation of Haumea's ring system

Observations using adaptive optics at the Keck Observatory have shown that Haumea is orbited by two moons . The larger of the two, Hiʻiaka , runs around the dwarf planet in about 49.5 days with an orbital eccentricity of 0.0513 at an average distance of 49,880 km. The smaller one, Namaka , is 25,657 km apart; its orbital period is 18.3 days. The orbital planes of the moons are tilted about 13 ° to each other, their masses are 79 ± 0.11e19  kg and ≈ 1.79e18  kg specified.

In Hawaiian mythology , Hi'iaka and Namaka are daughters of Haumea, the goddess of fertility, who were created from different parts of Haumea's body. The names of the moons allude to their presumed formation as fragments of Haumea after the collision with another object.

During a star occultation on January 21, 2017, it was discovered that Haumea has a 70 km wide ring with a diameter of about 4,574 km. This means that the ring system is only around 1,300 km away from the dwarf planet. Haumea is thus the third planetoid with rings after the centaurs Chariklo and Chiron , but in contrast to them, it moves outside the orbit of Neptune in the Kuiper belt. The ring lies in the same plane as Haumea's equator and Hi'iaka's orbit and is in 3: 1 resonance to Haumea's period of rotation, which means that Haumea rotates three times faster than the ring material. Research has shown that the ring contributes about 5% to the overall brightness of the Haumea system.

The Haumea 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 Haumea's
equator
Date of discovery
Date of publication
(136108) Haumea 1595.0 100.00 4.0 · 10 21 - - - - October 1, 1999
September 21, 2002
Ring system - - - 2287 ~ 0.49 ? ~ 0 January 21, 2017
October 11, 2017
Namaka
(Haumea II)
160.0 10.03 1.8 · 10 18 25657 18.2783 0.249 113.013 June 30, 2005 December 1, 2005
0
Hiʻiaka
(Haumea I)
320.0 20.06 1.8 · 10 19 49880 49,462 0.0513 126.356 January 26, 2005
July 29, 2005

See also

literature

  • N. Pinilla-Alonso, R. Brunetto, J. Licandro, R. Gil-Hutton, TL Roush, G. Strazzulla: The surface of (136108) Haumea (2003 EL 61 ), the largest carbon-depleted object in the trans- Neptunian belt . In: Astronomy & Astrophysics . tape 496 , no. 2 . EDP ​​Sciences, March 2009, pp. 547–556 , doi : 10.1051 / 0004-6361 / 200809733 , arxiv : 0803.1080 , bibcode : 2009A & A ... 496..547P .
  • ME Brown et al .: Keck Observatory Laser Guide Star Adaptive Optics Discovery and Characterization of a Satellite to the large Kuiper Belt Object 2003 EL61. In: The Astrophysical Journal . Volume 632 (October 10, 2005)
  • ME Brown et al .: Satellites of the largest Kuiper belt objects. In preparation for Astrophysical Journal Letters (November 2005)

Web links

Commons : 136108 Haumea  - Collection of images, videos and audio files

Individual evidence

  1. a b (136108) Haumea in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved June 7, 2018. Template: JPL Small-Body Database Browser / Maintenance / Alt
  2. v ≈ π * a / period (1 + sqrt (1-e²))
  3. a b c Alexandra C. Lockwood, Michael E. Brown, John Stansberry: The size and shape of the oblong dwarf planet Haumea . In: Earth, Moon and Planets . 111, No. 3-4, March 2014, pp. 127-137. arxiv : 1402.4456 . doi : 10.1007 / s11038-014-9430-1 .
  4. ^ A b E. T. Dunham, SJ Desch, L. Probst: Haumea's Shape, Composition, and Internal Structure . In: The Astrophysical Journal . 877, No. 1, April 2019, p. 11. arxiv : 1904.00522 . bibcode : 2019ApJ ... 877 ... 41D . doi : 10.3847 / 1538-4357 / ab13b3 .
  5. a b c D. Ragozzine; ME Brown: Orbits and Masses of the Satellites of the Dwarf Planet Haumea (2003 EL 61 ) . In: The Astronomical Journal . 137, No. 6, April 27, 2009, pp. 4766-4776. arxiv : 0903.4213 . doi : 10.1088 / 0004-6256 / 137/6/4766 .
  6. a b c Chadwick A. Trujillo, Michael E. Brown, Kristina Barkume, Emily Shaller, David L. Rabinowitz: The Surface of 2003 EL 61 in the Near Infrared . In: Astrophysical Journal . 655, No. 2, 2007, pp. 1172-1178. arxiv : astro-ph / 0601618 . bibcode : 2007ApJ ... 655.1172T . doi : 10.1086 / 509861 .
  7. D. Ragozzine; ME Brown: Candidate Members and Age Estimate of the Family of Kuiper Belt Object 2003 EL 61 . In: The Astronomical Journal . 134, No. 6, September 4, 2007, pp. 2160-2167. arxiv : 0709.0328 . bibcode : 2007AJ .... 134.2160R . doi : 10.1086 / 522334 .
  8. a b c 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 .
  9. Jason Davis: Planetary Society-funded telescopes help find ring around Haumea, a distant dwarf planet. Planetary Society , October 11, 2017, accessed October 11, 2017 .
  10. (136108) Haumea at the IAU Minor Planet Center (English). Retrieved June 7, 2018.
  11. 10. Planet “googled”? intern.de, August 10, 2005, accessed October 30, 2017 .
  12. J. Hecht: Astronomer denies improper use of web data. New Scientist, September 21, 2005, accessed October 30, 2017 .
  13. ^ R. Courtland: Controversial dwarf planet finally named “Haumea”. New Scientist, September 18, 2008, accessed October 30, 2017 .
  14. Michael E. Brown: The electronic trail of the discovery of 2003 EL61. Retrieved October 30, 2017 .
  15. MPC: List Of Transneptunian Objects , as of September 2008
  16. a b press release: IAU names fifth dwarf planet Haumea. IAU, September 17, 2008, accessed October 30, 2017 .
  17. Kelly Beatty: Haumea: Dwarf-Planet Name Game. Sky & Telescope, September 19, 2008, accessed October 30, 2017 .
  18. ^ Günter Paul: Dwarf planets: Haumea or Ataecina? FAZ , September 25, 2008, accessed October 30, 2017 .
  19. AstDyS: (136108) Haumea. Universita di Pisa, accessed June 7, 2018 .
  20. D. Rabinowitz et al. a .: Photometric Observations Constraining the Size, Shape, and Albedo of 2003 El61, a Rapidly Rotating, Pluto-Sized Object in the Kuiper Belt (September 2005)
  21. P. Lacerda et al. a .: Densities of Solar System Objects from their Rotational Lightcurves (December 2006)
  22. J. Stansberry et al. a .: Physical properties of Kuiper belt objects and Centaurs: Constraints from Spitzer Space Telescope (February 2007)
  23. ^ G. Tancredi: Physical and dynamical characteristics of icy “dwarf planets” (plutoids) . IAU. April 1, 2010. Retrieved January 29, 2019.
  24. E. Lellouch et al. a .: “TNOs are cool”: A survey of the trans-neptunian region. II. The thermal lightcurve of (136108) Haumea (June 2010)
  25. S. Fornasier et al. a .: “TNOs are cool”: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of 9 bright targets at 70-500 μm (April 2013, PDF)
  26. M. Mommert et al. a .: Remnant planetesimals and their collisional fragments: Physical characterization from thermal-infrared observations (2013)
  27. ^ M. Brown .: How many dwarf planets are there in the outer solar system? (November 2018)
  28. Press release: Kuiper-belt Object Was Broken up by Massive Impact 4.5 Billion Years Ago, Study Shows. CalTech , March 14, 2007, accessed October 30, 2017 .
  29. Colin Snodgrass, Benoit Carry, Christophe Dumas, Olivier Hainaut: Characterization of candidate members of (136108) Haumea's family . In: EDP Sciences (Ed.): Astronomy and Astrophysics . 511, March 12, 2010, p. A72. arxiv : 0912.3171 . bibcode : 2010A & A ... 511A..72S . doi : 10.1051 / 0004-6361 / 200913031 .
  30. Benoit Carry, Colin Snodgrass, Pedro Lacerda, Olivier Hainaut, Christophe Dumas: Characterization of candidate members of (136108) Haumea's family: II. Follow-up observations . In: EDP Sciences (Ed.): Astronomy & Astrophysics . 544, August 14, 2012, p. A137. arxiv : 1207.6491 . bibcode : 2012A & A ... 544A.137C . doi : 10.1051 / 0004-6361 / 201219044 .
  31. ^ SC Tegler, WM Grundy, W. Romanishin, GJ Consolmagno, K. Mogren, F. Vilas: Optical Spectroscopy of the Large Kuiper Belt Objects 136472 (2005 FY 9 ) and 136108 (2003 EL 61 ) . In: Astronomical Journal . 133, No. 2, 2007, pp. 526-530. arxiv : astro-ph / 0611135 . bibcode : 2007AJ .... 133..526T . doi : 10.1086 / 510134 .
  32. HORIZONS web interface. JPL Solar System Dynamics , accessed October 6, 2008 .
  33. Thomas Müller: Haumea - surprise with ring. In: Regiomontanus Bote. - The journal of the Nürnberger Astronomische Arbeitsgemeinschaft eV, Volume 31, 1/2018, pp. 11-14.
  34. Photometric Observations Constraining the Size, Shape, and Albedo of 2003 El61, a Rapidly Rotating, Pluto-Sized Object in the Kuiper Belt , arxiv : astro-ph / 0509401
  35. ^ The Astrophysical Journal, 632: L45 – L48, 2005 October 10 (PDF; 312 kB) Retrieved June 19, 2010.