Since the year 2000, a number of Kuiper belt objects (KBOs) with diameters of between 500 and 1500 km (more than half that of Pluto) have been discovered. 50000 Quaoar, a classical KBO discovered in 2002, is over 1000 km across. Makemake and Haumea, both announced on 29 July 2005, are larger still. Other objects, such as 28978 Ixion (discovered in 2001) and 20000 Varuna (discovered in 2000) measure roughly 500 km across.[1] This has led gradually to the acceptance of Pluto as the largest member of the Kuiper belt.[citation needed]

The brightest known dwarf planets and other KBOs (with absolute magnitudes < 4.0) are:

Number Permanent
Designation[2] 		Provisional
Designation[2] 		Absolute
magnitude[3] 		Bond Albedo (%)[2] Semimajor axis
(AU)[3] 		Equatorial diameter
(km)[2] 		Date found[2] Discoverer[3] Diameter method[4]
134340 Pluto −0.8 72 39.4 2377 1930 C. Tombaugh direct imaging
136472 Makemake 2005 FY9 −0.2 80 45.6 1430 2005 M. Brown, C. Trujillo, D. Rabinowitz occultation
136108 Haumea 2003 EL61 0.2 51 43.3 1595 2003 Sierra Nevada Observatory (unofficial) occultation
Charon S/1978 P 1 1.0 20 to 50 (geometric) 39.4 1212 1978 J. Christy direct imaging
90482 Orcus 2004 DW 2.2 23 39.3 910 2004 M. Brown, C. Trujillo, D. Rabinowitz thermal
50000 Quaoar 2002 LM60 2.4 11 43.7 1070 2002 C. Trujillo, M. Brown thermal
174567 Varda 2003 MW12 3.2 10 46.1 705 2003 J. A. Larsen estimated
55565 2002 AW197 3.3 11 47.2 768 2002 NEAT thermal
55636 2002 TX300 3.4 88 43.2 286 2002 NEAT Haumea family, estimated
202421 2005 UQ513 3.5 20 43.2 498 2005 Palomar estimated
307261 2002 MS4 3.6 5 42.0 934 2002 C. Trujillo, M. Brown thermal
208996 2003 AZ84 3.6 10 39.4 772 2003 C. Trujillo, M. Brown thermal
20000 Varuna 2000 WR106 3.6 11 42.3 678 2000 Spacewatch thermal
55637 2002 UX25 3.6 11 42.5 665 2002 Spacewatch thermal
28978 Ixion 2001 KX76 3.6 14 39.8 617 2001 DES thermal
145452 2005 RN43 3.7 11 41.6 679 2005 A. C. Becker, A. W. Puckett, J. Kubica thermal
120178 2003 OP32 3.9 70?[4] 43.4 218?[4] 2003 M. Brown, C. Trujillo, D. Rabinowitz Haumea family, estimated

See also

References

  1. ^ Audrey Delsanti & David Jewitt. "The Solar System Beyond The Planets" (PDF). Institute for Astronomy, University of Hawaii. Archived from the original (PDF) on 2007-01-29. Retrieved 2007-03-09.
  2. ^ a b c d e Johnston, W. R. (7 October 2018). "List of Known Trans-Neptunian Objects". Retrieved 6 February 2019.
  3. ^ a b c "List of Transneptunian Objects". Minor Planet Center. Retrieved 6 February 2019.
  4. ^ a b c Brown, M. (12 November 2018). "How many dwarf planets are there?". Retrieved 6 February 2019.
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