Rotational properties of the Haumea family members and candidates: Short-term variability
Abstract
Haumea is one of the largest known Trans-Neptunian Objects (TNOs) with several anomalous characteristics. It is a fast rotator with a double-peak period of 3.92 h. Its spectrum is dominated by water ice features and the high albedo suggests nearly pure water ice on the surface. It has two known satellites and a family of at least ten TNOs with very similar proper orbital parameters and spectral properties. The formation of this peculiar family (Haumea, its two moons and, dynamically related bodies) is not well understood despite various models that have been proposed during the past few years.In order to improve our understanding of the formation of this family, we have examined the rotational properties of the family members and candidates (i.e. objects with similar proper orbital elements to the family members but without water ice on their surface or without observations to detect surface water). We report new short-term variability for 5 family members and 7 candidates from data collected over the past five years using multiple ground-based facilities. Thanks to our study, all the Haumea family members have a short-term variability study.From rotational data, assuming fluid-like rubble-pile structure, we constrain ellipsoidal axis ratios for individual objects and set a lower limit to densities. We also compared lightcurve amplitude and rotational frequency distributions for the family members, candidates, and unrelated TNOs to search for additional clues to the progenitor and the formation of this family.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #47
- Pub Date:
- November 2015
- Bibcode:
- 2015DPS....4720301T