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THE IMCCE VIRTUAL OBSERVATORY
SOLAR SYSTEM PORTAL
Observatoire de Paris / CNRS

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The Virtual Observatory Sky Body Tracker

Documentation

The documentation of SkyBoT is composed of the following documents:
  • SkyBoT main page: describes the SkyBoT project and its web service
  • Release notes: describes the evolution and the releases of SkyBoT
  • HOWTO: explains how to fill the query forms
  • FAQ: the frequently asked questions page
  • Sso classes: describes how asteroid and comet classes are defined in SkyBoT
If you can't find an answer to your question or if you have comments about the SkyBoT service, feel free to contact the project team.
 Asteroid population classes 
1. Definition of population classes of asteroids in SkyBoT
2. Graphical representation
3. Definition of population of comets in SkyBoT

UPDATED CLASSIFICATION (Oct. 2014)
Old classes

1. Definition of population classes of asteroids in SkyBoT ^
The following table and figure show how the asteroid population is classified in SkyBoT, as defined by the international community according to the characteristics of their orbits.
PopulationSemi-major axis (AU)Aphelion or Perihelion (AU) (*)Comment
Vulcanoid 0.08 ≤ a < 0.21 Yet to be discovered
NEA>Atira 0.21 ≤ a < 1.0 a(1+e) < 0.983 Handful known
NEA>Aten 0.21 ≤ a < 1.0 a(1+e) ≥ 0.983 ~6% of Near Earth Asteroids
NEA>Apollo 1.0 < a < 2.0 a(1-e) < 1.017 ~62% of Near Earth Asteroids
NEA>Amor 1.0 < a < 2.0 1.017 ≤ a(1-e) < 1.3 ~32% of Near Earth Asteroids
Mars-Crosser>Deep 1.0 < a < 2.0 1.3 ≤ a(1-e) ≤ 1.58
Mars-Crosser>Shallow 1.0 < a < 2.0 1.58 ≤ a(1-e) ≤ 1.666
Hungaria 1.0 < a < 2.0 a(1-e) > 1.666
MB>Inner 2.0 ≤ a < 2.5 Inner Main Belt
MB>Middle 2.5 ≤ a < 2.82 Middle Main Belt
MB>Outer 2.82 ≤ a < 3.27 Outer Main Belt
MB>Cybele 3.27 ≤ a < 3.7
MB>Hilda 3.7 ≤ a < 4.6
Trojan 4.6 ≤ a < 5.5 Jupiter Trojans (L4 and L5)
Centaur 5.5 ≤ a < 30.1
KBO>Classical 30.1 ≤ a < 2000.0 Kuiper belt
KBO>Detached 30.1 ≤ a < 2000.0 e ≥ 0.24 Kuiper belt
KBO>SDO 30.1 ≤ a < 2000.0 a(1-e) ≤ 30.1*2^(2/3) * (1-0.24)Kuiper belt
KBO>Classical>Inner 30.1 ≤ a < 39.4 Kuiper belt
KBO>Classical>Main 39.4 ≤ a < 47.8 Kuiper belt
KBO>Classical>Outer 47.8 ≤ a < 2000.0 Kuiper belt
KBO>Resonnant x:y 30.1 ≤ a < 2000.0 a - (30.1*R^(2/3)) ≤ 0.35 Kuiper belt
IOC a ≥ 2000.0 Inner Oort cloud
(*): a = semi-major axis, e = eccentriciy, p = period, R = resonnance x:y, e.g. 5:4, 4:3, 11:8, ...
2. Graphical representation ^
Asteroid population classes
3. Definition of population of comets in SkyBoT ^
The following table and figure show how the comet population is classified in SkyBoT, as defined by the international community according to the characteristics of their orbits.
PopulationOrbital Period (year)EccentricityTisserand's invariantComments
Long-Period P > 200
Short-Period P ≤ 200
Short-Period>Jupiter-family e < 1 TJ > 2
Short-Period>Halley-type e < 1 TJ ≤ 2