Cold and Hot Populations: Physical Characteristics
In addition to the distinct orbital characteristics the two populations display different physical characteristics.
The difference in colour between the red cold population and more heterogeneous hot population was observed as early as in 2002. Recent studies, based on a larger data set, indicate the cut-off inclination of 12° (instead of 5°) between the cold and hot populations while confirming the distinction between the homogenous red cold population and the bluish hot population.
Another difference between the low-inclination (cold) and high-inclination (hot) classical objects is the observed number of binary objects. Binaries are quite common on low-inclination orbits and are typically similar-brightness systems. Binaries are less common on high-inclination orbits and their components typically differ in brightness. This correlation, together with the differences in colour, support further the suggestion that the currently observed classical objects belong to at least two different overlapping populations, with different physical properties and orbital history.
Read more about this topic: Classical Kuiper Belt Object
Famous quotes containing the words cold and, cold, hot and/or physical:
“Cold and hunger seem more friendly to my nature than those methods which men have adopted and advise to ward them off.”
—Henry David Thoreau (1817–1862)
““Peter is poor,” said noble Paul,
“And I have always been his friend:
And, though my means to give are small,
At least I can afford to lend.
How few, in this cold age of greed,
Do good, except on selfish grounds!
But I can feel for Peter’s need,
And I WILL LEND HIM FIFTY POUNDS!””
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)
“More than I, if truth were told,
Have stood and sweated hot and cold,
And through their veins in ice and fire
Fear contended with desire.”
—A.E. (Alfred Edward)
“When we say that pleasure is the end, we do not mean the pleasure of the profligate or that which depends on physical enjoyment—as some think who do not understand our teachings, disagree with them, or give them an evil interpretation—but by pleasure we mean the state wherein the body is free from pain and the mind from anxiety.”
—Epicurus (c. 341–271 B.C.)