(55565) 2002 AW 197

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Asteroid
(55565) 2002 AW 197
2002 AW197 by the Hubble Space Telescope
2002 AW 197 by the Hubble Space Telescope
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type CKBO  ( «Hot» )  or
DO (E SDO ),
«Distant Object»
Major semi-axis 47.194  AU
eccentricity 0.132
Perihelion - aphelion 40.984 AU - 53.404 AU
Inclination of the orbit plane 24.4 °
Length of the ascending node 297.6 °
Argument of the periapsis 296.3 °
Time of passage of the perihelion March 31, 2078
Sidereal period 324 a 2.6 M.
Mean orbital velocity 4.307 km / s
Physical Properties
Medium diameter
Dimensions ≈ 4.1  ·  10 20 Template: Infobox asteroid / maintenance / mass kg
Albedo
Medium density ≈ 2.0 g / cm³
Rotation period 8.86 ± 0.01 h (0.369 d )
Absolute brightness 3.568 ± 0.046 mag
Spectral class C
B-V = 0.920 ± 0.020
VR = 0.560 ± 0.020
VI = 1.170 ± 0.010
BR = 1.480 ± 0.030
history
Explorer Chadwick A. Trujillo
Michael E. Brown
Eleanor F. Helin
Steven H. Pravdo
Kenneth J. Lawrence
Michael Hicks
Date of discovery January 10, 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.

(55565) 2002 AW 197 is a large trans-Neptunian object in the Kuiper belt , which is classified as Cubewano (CKBO) or an extended Scattered Disk Object (DO) in terms of its orbit dynamics . Because of its size, the asteroid is a dwarf planet candidate .

discovery

(55565) 2002 AW 197 was discovered on January 10, 2002 by a team of astronomers consisting of Chad Trujillo , Mike Brown , Eleanor "Glo" Helin , Steven H. Pravdo, Kenneth Lawrence and Michael Hicks with the 1.2 m Oschin Schmidt telescope discovered at the Palomar Observatory of the California Institute of Technology ( California ). The discovery was announced on July 20, 2002, the planetoid was later given the minor planet number 55565 by the IAU .

After its discovery, in 2002 AW 197 could be identified on photos from December 29, 1997, which were taken as part of the NEAT and GEODSS programs at the Haleakalā Observatory ( Maui ), thus extending its observation period by five years calculate its orbit more precisely. Since then, the planetoid has been observed through various telescopes such as the Herschel and Spitzer space telescopes as well as earth-based telescopes. In April 2017, a total of 205 observations were made over a period of 20 years. The last observation so far was carried out in February 2019 at the Vegaquattro Observatory ( Piedmont ). (As of March 12, 2019)

properties

The orbit of 2002 AW 197 (white) compared to those of Pluto (purple) and Neptune (blue).

Orbit

2002 AW 197 orbits the sun in 324.22 years on a slightly elliptical orbit between 40.98  AU and 53.40 AU from its center. The orbit eccentricity is 0.132, the orbit is inclined 24.44 ° to the ecliptic . The planetoid is currently 45.35 AU from the sun. He will next pass perihelion in 2078, so the last perihelion should have occurred in 1754.

The semi-major axis of 2002 AW 197 is located on the outer edge of the Kuiper belt, the so-called Kuiper cliff (English Kuiper cliff ) at 47 AU.

Marc Buie ( DES ) classifies the planetoid as an extended SDO (ESDO or DO ), while the Minor Planet Center him as Cubewano classifies, where he ground dynamically to the "hot" classical KBO heard; the latter also lists it as a non-SDO and generally as a “distant object” .

Size and rotation

Originally it was assumed that 2002 AW 197 had an albedo of 0.04. Based on this assumption, a diameter of 1,500 km was concluded. However, later studies with the Herschel and Spitzer space telescopes yielded an albedo value of 0.112 ± 0.012, so that the diameter had to be corrected to 768 ± 38 kilometers. Based on this diameter, the total surface is around 1,853,000 km². The apparent brightness of 2002 AW 197 is 19.99  m , the mean surface temperature is estimated at 39 to 40 K (−233 to −234 ° C) based on the  distance to the sun.

It is assumed that 2002 AW 197 is in hydrostatic equilibrium due to its mass and therefore meets the criteria for classification as a dwarf planet . Mike Brown assumes that it is most likely a dwarf planet; Gonzalo Tancredi also accepted AW 197 2010 as a dwarf planet in 2002 , but did not propose to the IAU that it be officially recognized as such.

Using light curve observations , 2002 AW 197 rotates once around its axis in 8 hours and 51.6 minutes. This means that in a 2002 AW 197 year it performs 320778.8 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%.

Determination of the diameter for 2002 AW 197
year Dimensions km source
2002 886.0 +115.0−131.0 Margot et al. a.
2005 700.0 ± 50.0 Tegler u. a.
2005 700.0 ± 50.0 Stansberry et al. a.
2007 734.0 +123.0−135.0 Cruikshank et al. a.
2007 734.6 +116.4−108.3 Stansberry et al. a.
2008 705.0 Tancredi
2009 742.0 +98.0−104.0 Brucker et al. a.
2010 735.0 Tancredi
2013 686.0 Mommert et al. a.
2014 768.0 +39.0−48.0 Vilenius et al. a.
2016 701.41 LightCurve DataBase
2018 693.0 Brown
The most precise determination is marked in bold .

surface

Spectral analyzes of the European Southern Observatory show a clear red color; the presence of water ice on the surface could not be detected, indicating the presence of organic material . This is in contrast to Quaoar , which is also a reddish color.

See also

Web links

Commons : (55565) 2002 AW197  - Collection of Images, Videos and Audio Files

Individual evidence

  1. ↑ a b MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Accessed March 12, 2019.
  2. ↑ 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 .
  3. ^ A b Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 12, 2019.
  4. ^ A b Marc W. Buie : Orbit Fit and Astrometric record for 55565 . SwRI (Space Science Department). Retrieved March 12, 2019.
  5. ↑ a b c (55565) 2002 AW197 at the IAU Minor Planet Center (English) Retrieved March 12, 2019.
  6. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  7. ↑ a b c d e E. Vilenius u. a .: “TNOs are cool”: A survey of the trans-Neptunian region X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observations (PDF) . In: Astronomy and Astrophysics . 564, No. A35, March 25, 2014, p. 18. arxiv : 1403.6309 . doi : 10.1051 / 0004-6361 / 201322416 .
  8. ↑ Calculated on the basis of a diameter of 768 km and an assumed average density of 2.0 g / cm³, which is typical for TNO.
  9. ↑ J. Ortiz et al. a .: Short-term rotational variability of eight KBOs from Sierra Nevada Observatory . In: Astronomy and Astrophysics . 447, No. 3, March 2006, pp. 1131-1144. bibcode : 2006A & A ... 447.1131O . doi : 10.1051 / 0004-6361: 20053572 .
  10. ↑ a b LCDB Data for (55565) 2002AW197 . MinorPlanetInfo. 2016. Accessed March 12, 2019.
  11. ↑ a b c S. Tegler u. a .: Two Color Populations of Kuiper Belt and Centaur Objects and the Smaller Orbital Inclinations of Red Centaur Objects (PDF) . In: The Astronomical Journal . 152, No. 6, December 2016, p. 210, 13. bibcode : 2016AJ .... 152..210T . doi : 10.3847 / 0004-6256 / 152/6/210 .
  12. ↑ I. Belskaya et al. a .: Updated taxonomy of trans-neptunian objects and centaurs: Influence of albedo . In: Icarus . 250, April 2015, pp. 482-491. bibcode : 2015Icar..250..482B . doi : 10.1016 / j.icarus.2014.12.004 .
  13. ↑ MPC : MPEC 2002-O30: 2002 AW197 . IAU . July 20, 2002. Retrieved March 12, 2019.
  14. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 12, 2019.
  15. ↑ (55565) 2002 AW197 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 12, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  16. ↑ MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 12, 2019.
  17. ↑ (55565) 2002 AW197 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  18. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 12, 2019.
  19. ^ A b G. Tancredi: Physical and dynamical characteristics of icy “dwarf planets” (plutoids) (PDF) . In: International Astronomical Union (Ed.): Icy Bodies of the Solar System: Proceedings IAU Symposium No. 263, 2009 . 2010. doi : 10.1017 / S1743921310001717 . Retrieved March 12, 2019.
  20. ↑ J. Margot et al. a .: The size and albedo of KBO 2002 AW 197 . In: American Astronomical Society, DPS Meeting . 34, September 2002, p. 871. bibcode : 2002DPS .... 34.1703M .
  21. ↑ S. Tegler u. a .: The period of rotation, shape, density, and homogeneous surface color of the Centaur 5145 Pholus . In: Icarus . 175, No. 2, June 2005, pp. 390-396. bibcode : 2005Icar..175..390T . doi : 10.1016 / j.icarus.2004.12.011 .
  22. ↑ J. Stansberry et al. a .: Albedos, Diameters (and a Density) of Kuiper Belt and Centaur Objects (PDF) . In: American Astronomical Society, DPS meeting . 37, August 2005, p. 737. bibcode : 2005DPS .... 37.5205S .
  23. ↑ D. Cruikshank et al. a .: Physical Properties of Transneptunian Objects (PDF) . In: University of Arizona Press: Protostars and Planets . 951, 2006, pp. 879-893. bibcode : 2007prpl.conf..879C .
  24. ↑ J. Stansberry et al. a .: Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope (PDF) . In: University of Arizona Press . 592, No. 161-179, February 20, 2007. arxiv : astro-ph / 0702538 . bibcode : 2008ssbn.book..161S .
  25. ^ G. Tancredi, S. Favre: DPPH List . In: Dwarf Planets and Plutoid Headquarters, from Which are the dwarfs in the solar system? . August. Retrieved March 12, 2019.
  26. ↑ M. Brucker et al. a .: High Albedos of Low Inclination Classical Kuiper Belt Objects (PDF) . In: Icarus . January 1, 2009, p. 26. arxiv : 0812.4290 . bibcode : 2012A & A ... 546A..86P . doi : 10.1016 / j.icarus.2008.12.040 .
  27. ↑ M. Mommert et al. a .: Remnant planetesimals and their collisional fragments: Physical characterization from thermal-infrared observations . September 23, 2013. Accessed March 12, 2019.
  28. ↑ D. Ragozzine, M. Brown : Candidate Members and Age Estimate of the Family of Kuiper Belt Object 2003 EL61 (PDF) . In: The Astronomical Journal . 134, No. 6, December 2007, pp. 2160-2167. arxiv : 0709.0328 . bibcode : 2007AJ .... 134.2160R . doi : 10.1086 / 522334 . Retrieved March 12, 2019. , table on p. 8