A Dearth of Small Members in the Haumea Family Revealed by the OSSOS Survey

Abstract

While collisional families are common in the asteroid belt, only one is known in the Kuiper belt, linked to the dwarf planet Haumea. The characterization of Haumea's family helps to constrain its origin and, more generally, the collisional history of the Kuiper belt. However, the size distribution of the Haumea family is difficult to constrain from the known sample, which is affected by discovery biases. Here, we use the Outer Solar System Origins Survey (OSSOS) Ensemble to look for Haumea family members. In this OSSOS XVI study we report the detection of three candidates with small ejection velocities relative to the family formation centre. The largest discovery, 2013 UQ15, is conclusively a Haumea family member, with a low ejection velocity and neutral surface colours. Although the OSSOS Ensemble is sensitive to Haumea family members to a limiting absolute magnitude (Hr) of 9.5 (inferred diameter of ~90 km), the smallest candidate is significantly larger, Hr = 7.9. The Haumea family members larger than approximately 20 km in diameter must be characterized by a shallow H-distribution slope in order to produce only these three large detections. This shallow size distribution suggests that the family formed in a graze-and-merge scenario, not a catastrophic collision.

11 pages, 3 figures, 3 tables

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Cited by in corpus (6)

• OSSOS: The Eccentricity and Inclination Distributions of the Stable Neptunian Trojans
• The formation of Haumea and its family via binary merging
• From Planetesimals to Dwarf Planets by Pebble Accretion
• Understanding the trans-Neptunian Solar system: Reconciling the results of serendipitous stellar occultations and the inferences from the cratering record
• Trans-Neptunian Space and the Post-Pluto Paradigm
• The Surfaces of Small to Mid-Size Plutinos: Evidence of an Association Between Inclination and Surface Type