On the Detection of Two New Transneptunian Binaries from the CFEPS Kuiper Belt Survey

TL;DR

This paper reports the discovery of two new near-equal mass Trans-Neptunian Binaries from the CFEPS survey, including the highest inclination binary known, and estimates their occurrence rates in the Kuiper belt.

Contribution

It introduces two newly identified Trans-Neptunian Binaries and provides the first estimates of their frequency in different Kuiper belt populations.

Findings

Discovered two new near-equal mass TNBs, L4k12 and L5c02.

L4k12 has the highest orbital inclination among known near-equal mass binaries.

Estimated binary fraction ranges from 1.5% to 20% in the cold classical Kuiper belt.

Abstract

We report here the discovery of an new near-equal mass Trans-Neptunian Binaries (TNBs) L5c02 and the and the putative detection of a second TNB (L4k12) among the year two and three detections of the Canada-France-Eclipic Plane Survey (CFEPS). These new binaries (internal designation L4k12 and L5c02) have moderate separations of 0.4" and 0.6" respectively. The follow-up observation confirmed the binarity of L5c02, but L4k12 are still lack of more followup observations. L4k12 has a heliocentric orbital inclination of ~ 35?degree, marking this system as having the highest heliocentric orbital inclination among known near-equal mass binaries. Both systems are members of the classical main Kuiper belt population. Based on the sample of objects searched we determine that the fraction of near-equal mass wide binaries with separations > 0.4" is 1.5% to 20% in the cold main classical Kuiper belt and, if our detection the binarity L4k12 holds, 3% to 43% in the hot main classical objects are binary. In this manuscript we describe our detection process, the sample of objects surveyed, our confirmation observations.