Space Topics: Trans-Neptunian Objects
Notable Trans-Neptunian Objects
Since 1992, more than a thousand trans-Neptunian objects have been discovered. Most
of these objects have only been seen as points of light moving across the
sky, so their diameters are not well known. Therefore, it is customary
when comparing these objects to list their “absolute magnitude,” a
measure of the amount of light they reflect normalized to their distance from
an observer. All else being equal, a brighter absolute magnitude translates
to a larger diameter.
Following is a table of some of the better known trans-Neptunian objects,
listed in order of their absolute magnitude. Diameters are only listed if they have been observed through a stellar occultation or through a resolved picture of the object’s
disk.
Permanent Name |
Provisional Name |
Absolute Magnitude |
Perihelion, AU |
Aphelion, AU |
Inclination, Degrees |
Diameter (if known), kilometers |
136199 Eris |
2003 UB313 |
-1.1 |
38.17 |
97.61 |
43.993 |
~2,400 |
Pluto |
|
-1.0 |
30.164 |
48.494 |
17.16 |
2,350±50 |
|
2005 FY9 |
-0.2 |
38.666 |
52.809 |
29.0 |
~1,600 |
|
2003 EL61 |
0.1 |
35.161 |
51.525 |
28.2 |
1,320-1,550 |
Charon |
S/1978 P1 |
1.0 |
30.164 |
48.494 |
17.16 |
1,207.2 |
90377 Sedna |
2003 VB12 |
1.6 |
76.032 |
928.048 |
11.932 |
~1,600 |
90482 Orcus |
2004 DW |
2.3 |
30.784 |
48.057 |
20.6 |
~1,600 |
50000 Quaoar |
2002 LM60 |
2.6 |
41.980 |
45.019 |
8.0 |
1,260 +/- 190 |
28978 Ixion |
2001 KX76 |
3.2 |
30.308 |
49.127 |
19.6 |
|
55565 |
2002 AW197 |
3.3 |
|
|
24.4 |
|
20000 Varuna |
2000 WR106 |
3.7 |
40.804 |
45.210 |
17.2 |
|
| |
2004 XR190 |
4.5 |
51.038 |
63.780 |
46.735 |
|
38628 Huya |
2000EB173 |
4.7 |
28.554 |
50.950 |
15.5 |
|
19521 Chaos |
1998 WH24 |
4.9 |
40.925 |
50.376 |
12.1 |
|
53311 Deucalion |
1999 HU11 |
6.6 |
41.579 |
47.157 |
0.4 |
|
38083 Rhadamanthus |
1999 HX11 |
6.7 |
33.212 |
45.243 |
12.7 |
|
|
1992 QB1 |
7.2 |
40.875 |
46.592 |
2.2 |
|
|
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