Evidence for Two Populations of Classical Transneptunian Objects: The Strong Inclination Dependence of Classical Binaries

Abstract

We have searched 101 Classical transneptunian objects for companions with the Hubble Space Telescope. Of these, at least 21 are binary. The heliocentric inclinations of the objects we observed range from 0.6-34 degrees. We find a very strong anticorrelation of binaries with inclination. Of the 58 targets that have inclinations of less than 5.5 degrees, 17 are binary, a binary fraction of 29 +7/-6%. All 17 are similar-brightness systems. On the contrary, only 4 of the 42 objects with inclinations greater than 5.5 degrees have satellites and only 1 of these is a similar-brightness binary. This striking dichotomy appears to agree with other indications that the low eccentricity, non-resonant Classical transneptunian objects include two overlapping populations with significantly different physical properties and dynamical histories.

32 pages, 4 figures, 2 tables in press for Icarus volume 194 Note added in proof and reference updates in this corrected version

References in corpus (4)

• Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune
• Binaries in the Kuiper Belt
• Production of trans-Neptunian binaries through chaos-assisted capture
• Discovery of a Binary Centaur

Cited by in corpus (8)

• High Albedos of Low Inclination Classical Kuiper Belt Objects
• The Correlated Colors of Transneptunian Binaries
• Color-Inclination Relation of the Classical Kuiper Belt Objects
• On a Scattered-Disk Origin for the 2003 El61 Collisional Family - an Example of the Importance of Collisions on the Dynamics of Small Bodies
• Detection of Additional Members of the 2003 EL61 Family via Infrared Spectroscopy
• Mutual Orbits and Masses of Six Transneptunian Binaries
• Is the Missing Ultra-Red Material Colorless Ice?
• The Diverse Solar Phase Curves of Distant Icy Bodies. II. The Cause of the Opposition Surges and Their Correlations