(42301) 2001 UR163

(42301) 2001 UR163
Discovery[1]
Discovered by Kitt Peak (695)
Discovery date October 21, 2001
Designations
MPC designation (42301) 2001 UR163
Alternate name(s) none
Minor planet
category		 TNO (SDO)[2]
9:4 resonance[3]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 66.106 AU (9889.356 Gm)
Perihelion 36.756 AU (5498.582 Gm)
Semi-major axis 51.431 AU (7693.969 Gm)
Eccentricity 0.285
Orbital period 368.85 a (134721.208 d)
Average orbital speed 4.07 km/s
Mean anomaly 68.401°
Inclination 0.752°
Longitude of ascending node 301.769°
Argument of perihelion 342.639°
Physical characteristics
Dimensions 636 km (assumed)[5]
Mass 2.7×1020? kg
Mean density 2.0? g/cm³
Equatorial surface gravity 0.1778? m/s²
Escape velocity 0.3362? km/s
Sidereal rotation
period		 ? d
Albedo 0.09? (assumed)
Temperature ~39 K
Spectral type (Super red;highest B-R) B-V=1.44; V-R=0.84; B-R=2.28
Apparent magnitude 21.2[6]
Absolute magnitude (H) 3.97[4]

(42301) 2001 UR163, also written as (42301) 2001 UR163, is a very likely dwarf planet[7] that resides in the scattered disc. It was discovered on October 21, 2001 by the Deep Ecliptic Survey (DES) program at Kitt Peak. Light-curve-amplitude analysis shows only small deviations, suggesting that 2001 UR163 is a spheroid with small albedo spots and hence a dwarf planet.[8]

2001 UR163 has the reddest color index of any object in the Solar System. On October 31, 2002, the 3.6 meter Canada-France-Hawaii telescope observed 2001 UR163 set a record red reading of B-R=2.28. This makes 2001 UR163 even redder than 5145 Pholus, (119070) 2001 KP77, 90377 Sedna, and comet C/2001 T4. Reddening of the spectrum is caused by cosmic irradiaton by ultraviolet radiation and charged particles. Becoming bluer in the spectrum is caused by impact collisions exposing the interior of an object. In the visible spectrum 2001 UR163 would appear orange-brown depending on its albedo.

It is currently 50.6 AU from the Sun[6], and came to perihelion around 1937[4].

References

  1. ^ Marsden, Brian G. (2001-11-14). "MPEC 2001-V57: 2001 QX322, 2001 UR163, 2001 VN71". IAU Minor Planet Center. Harvard-Smithsonian Center for Astrophysics. http://www.cfa.harvard.edu/mpec/K01/K01V57.html. Retrieved 2010-01-06.  (K01UG3R*)
  2. ^ "List Of Centaurs and Scattered-Disk Objects". Minor Planet Center. http://www.minorplanetcenter.org/iau/lists/Centaurs.html. Retrieved 2008-09-25. 
  3. ^ Marc W. Buie (2003-10-23). "Orbit Fit and Astrometric record for 42301". SwRI (Space Science Department). http://www.boulder.swri.edu/~buie/kbo/astrom/42301.html. Retrieved 2008-09-25. 
  4. ^ a b c "JPL Small-Body Database Browser: 42301 (2001 UR163)". 2003-10-23 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=42301. Retrieved 2009-03-22. 
  5. ^ List of known trans-Neptunian objects
  6. ^ a b "AstDys (42301) 2001UR163 Ephemerides". Department of Mathematics, University of Pisa, Italy. Archived from the original on 2009-04-18. http://www.webcitation.org/query?id=1240086956292341. Retrieved 2009-03-19. 
  7. ^ Gonzalo Tancredi and Sofía Favre (13-Oct-2008?). "Dwarf Planet & Plutoid Headquarters". Portal Uruguayo de Astronomía. http://www.astronomia.edu.uy/dwarfplanet/list.html. Retrieved 2010-09-22.  (Which are the dwarfs in the Solar System?)
  8. ^ Tancredi, G., & Favre, S. (2008) Which are the dwarfs in the Solar System?. Depto. Astronomía, Fac. Ciencias, Montevideo, Uruguay; Observatorio Astronómico Los Molinos, MEC, Uruguay. Retrieved 10-08-2011

External links

(42300) 2001 UU140•(42301) 2001 UR163• (42302) 2001 VF10