Diagram showing several centaurs and other referencing objects with their V–R and B–V color indices plotted against one another. The red centaurs (5145 Pholus) are in the upper right, while the blue-grey centaurs (2060 Chiron) are grouped in the lower left of the diagram (bimodal color distribution of centaurs). An object's size (mean-diameter) is also estimated (only for centaurs, not for referencing objects).

Details

• The position of an object represents the two colour indices
  • horizontal axis V-B, blue colour index i.e. the difference in the magnitude of the object observed through a visual (green-yellow) and a blue filter
  • vertical axis R-V, red colour index, the difference in the magnitude between red and visual filters
• colour (slightly enhanced) represents the hue of the object; no albedo differences are currently displayed, in spite of the graph's title!
• the size of a sphere illustrates the object's size relative to others.
  • for a few large objects, the diameter drawn represents the current estimates (for known albedos)
  • for all the others, the diameter represents the absolute (V) magnitude of the object.
  • for Phoebe, Triton, and Mars (yellow labels), size is not shown to scale.