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:
“Reason now gazes above the realm of the dark but warm feelings as the Alpine peaks do above the clouds. They behold the sun more clearly and distinctly, but they are cold and unfruitful.”
—G.C. (Georg Christoph)
“By the road to the contagious hospital
under the surge of the blue
mottled clouds driven from the
northwest—a cold wind.”
—William Carlos Williams (1883–1963)
“The imperfect is our paradise.
Note that, in this bitterness, delight,
Since the imperfect is so hot in us,
Lies in flawed words and stubborn sounds.”
—Wallace Stevens (1879–1955)
“It seems to me that we have to draw the line in sibling rivalry whenever rivalry goes out of bounds into destructive behavior of a physical or verbal kind. The principle needs to be this: Whatever the reasons for your feelings you will have to find civilized solutions.”
—Selma H. Fraiberg (20th century)