(42301) 2001 UR 163

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Asteroid
(42301) 2001 UR 163
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type RKBO 4: 9 or
SDO ,
"Distant Object"
Major semi-axis 51.457  AU
eccentricity 0.287
Perihelion - aphelion 36.695 AU - 66.219 AU
Inclination of the orbit plane 0.75315 °
Length of the ascending node 301.4 °
Argument of the periapsis 343.2 °
Time of passage of the perihelion February 26, 1937
Sidereal period 369 a 1.6 M.
Mean orbital velocity 4.118 km / s
Physical Properties
Medium diameter approx. 561 km
Albedo 0.09-0.10
Absolute brightness 4.1 - 4.6 mag
Spectral class C
B-V = 1.290 ± 0.109
VR = 0.840 ± 0.048
VI = 1.452 ± 0.098
BR = 2.190 ± 0.130
history
Explorer James L. Elliot,
Susan D. Benecchi,
K. E. Washburn
Date of discovery October 21, 2001
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.

(42301) 2001 UR 163 is a large trans-Neptunian object that is classified as a resonant KBO (4: 9 resonance) in terms of orbital dynamics . Because of its size, the asteroid is a dwarf planet candidate . Its unusual red color, so far the reddest in the solar system, is particularly striking .

discovery

2001 UR 163 was discovered on October 21, 2001 by James Elliot, Susan Benecchi (–Kern) and KE Washburn as part of the Deep Ecliptic Survey project with the 4 m reflector telescope at the Kitt Peak Observatory ( Arizona ). The discovery was announced on November 14, 2001 together with 2001 QX 322 and 2001 VN 71 , the planetoid was later given the minor planet number 42301 by the IAU .

After its discovery, UR 163 could be identified in 2001 on photos from July 27, 1982, which were taken as part of the Digitized Sky Survey program (DSS) at the Siding Spring Observatory ( Australia ), thus extending its observation period by 19 years in order to calculate its orbit more precisely. Since then, UR 163 has been observed in 2001 with earth-based telescopes such as the Canada-France-Hawaii Telescope . In April 2017 there were a total of 157 observations over a period of 35 years. The last observation so far was carried out in October 2016 at the Pan-STARRS telescope (PS1) ( Maui ). (As of March 14, 2019)

properties

Orbit

2001 UR 163 orbits the sun in 369.13 years in an elliptical orbit between 36.69  AU and 66.22 AU from its center. The orbit eccentricity is 0.287, the orbit is 0.75 ° inclined to the ecliptic . The planetoid is currently 53.09 AU from the Sun. He last went through perihelion in early 1937; In 2006 UR 163 crossed the 50 AU limit in 2001 after crossing the entire Kuiper belt . The next perihelion should take place around the year 2306.

Marc Buie ( DES ) classifies the planetoid as RKBO ( 4: 9 resonance with Neptune ), while the Minor Planet Center classifies it as SDO ; the latter also generally lists it as a “distant object”.

size

A calculated diameter of 561 km is currently assumed; this value is based on an assumed reflectivity of 9% and an absolute brightness of 4.6  m . Based on this diameter, the total surface area is around 989,000 km². The apparent brightness of 2001 UR 163 is 21.54  m , the mean surface temperature is estimated at 39 K (−234 ° C) based on the distance from the sun  .

It can be assumed that 2001 UR 163 is in hydrostatic equilibrium and the asteroid is therefore a dwarf planet candidate , based on Mike Brown's taxonomic 5-class system , from which this diameter estimate comes. Mike Brown assumes that 2001 UR 163 is likely a dwarf planet. According to Gonzalo Tancredi, it is only possibly one.

Determination of the diameter for 2001 UR 163
year Dimensions km source
2008 607.0 Tancredi
2010 607.0 Tancredi
2015 531.5 LightCurve DataBase
2018 671.0 Johnston
2018 561.0 Brown
The most precise determination is marked in bold .

Surface and color

The light curve observations showed only small deviations, which indicates a spherical structure with small albedo spots.

2001 UR 163 has the reddest color index in the entire solar system. On October 31, 2002, the asteroid was observed by the 3.6 Canada-France-Hawaii Telescope , with a possibly record-breaking red index of B − R = 2.28. This makes 2001 UR 163 redder than (5145) Pholus , (119070) 2001 KP 77 , (90377) Sedna and the comet C / 2001 T4 .

Red tints in the spectrum are usually caused by cosmic weathering caused by ultraviolet radiation and charged particles from the sun. A blue shift occurs when meteor impacts reveal the subsurface of the surface of a celestial body. In 2001, UR 163 would appear orange to brown in visible light , depending on its albedo.

See also

Individual evidence

  1. ^ A b Marc W. Buie : Orbit Fit and Astrometric record for 42301 . SwRI (Space Science Department). Retrieved March 14, 2019.
  2. ^ A b Wm. R. Johnston: List of Known Trans-Neptunian Objects . Johnston's Archives. October 7, 2018. Retrieved March 14, 2019.
  3. ↑ a b MPC : MPEC List Of Centaurs and Scattered-Disk Objects . IAU . Retrieved March 14, 2019.
  4. ↑ a b MPC : MPEC 2010-S44: Distant Minor Planets (2010 OCT.11.0 TT) . IAU . September 25, 2010. Accessed March 14, 2019.
  5. ↑ a b c (42301) 2001 UR163 at the IAU Minor Planet Center (English) Retrieved March 14, 2019.
  6. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  7. ↑ a b LCDB Data for (42301) . MinorPlanetInfo. 2015. Accessed March 14, 2019.
  8. ↑ a b c O. Hainaut u. a .: Colors of minor bodies in the outer solar system. II. A statistical analysis revisited (PDF) . In: Astronomy and Astrophysics . 546, No. A115, September 10, 2012, p. 20. arxiv : 1209.1896 . bibcode : 2012A & A ... 546A.115H . doi : 10.1051 / 0004-6361 / 201219566 .
  9. ↑ N. Peixinho et al. a .: The bimodal colors of Centaurs and small Kuiper belt objects (PDF) . In: Astronomy and Astrophysics . 546, No. A86, June 14, 2012, p. 12. arxiv : 1206.3153 . bibcode : 2012A & A ... 546A..86P . doi : 10.1051 / 0004-6361 / 201219057 .
  10. ↑ MPC : MPEC 2001-V57: 2001 QX322, 2001 UR163, 2001 VN71 . IAU . November 14, 2001. Retrieved March 14, 2019.
  11. ↑ MPC : MPC / MPO / MPS Archive . IAU . Retrieved March 14, 2019.
  12. ↑ (42301) 2001 UR163 in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved March 14, 2019. Template: JPL Small-Body Database Browser / Maintenance / Alt
  13. ↑ (42301) 2001 UR163 in the database of the "Asteroids - Dynamic Site" (AstDyS-2, English).
  14. ↑ a b Mike Brown : How many dwarf planets are there in the outer solar system? . CalTech . November 12, 2018. Retrieved March 14, 2019.
  15. ↑ a b c 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 14, 2019.
  16. ^ G. Tancredi, S. Favre: DPPH List . In: Dwarf Planets and Plutoid Headquarters, from Which are the dwarfs in the solar system? . September. Retrieved March 14, 2019.
  17. ↑ D. Perna et al. a .: Colors and taxonomy of Centaurs and trans-Neptunian objects (PDF) . In: Astronomy and Astrophysics . 510, No. A53, February 2010. arxiv : 0912.2621 . bibcode : 2010A & A ... 510A..53P . doi : 10.1051 / 0004-6361 / 200913654 .