Rotational Properties of the Haumea Family Members and Candidates: Short-term Variability.

DOI: 
10.3847/0004-6256/151/6/148
Publication date: 
01/06/2016
Main author: 
Thirouin, Audrey
IAA authors: 
Ortiz, Jose Luis
Authors: 
Thirouin, Audrey;Sheppard, Scott S.;Noll, Keith S.;Moskovitz, Nicholas A.;Ortiz, Jose Luis;Doressoundiram, Alain
Journal: 
The Astronomical Journal
Refereed: 
Yes
Publication type: 
Article
Volume: 
151
Pages: 
148
Abstract: 
Haumea is one of the most interesting and intriguing trans-Neptunian objects (TNOs). It is a large, bright, fast rotator, and its spectrum indicates nearly pure water ice on the surface. It has at least two satellites and a dynamically related family of more than 10 TNOs with very similar proper orbital parameters and similar surface properties. The Haumean family is the only one currently known in the trans-Neptunian belt. Various models have been proposed, but the formation of the family remains poorly understood. In this work, we have investigated the rotational properties of the family members and unconfirmed family candidates with short-term variability studies, and report the most complete review to date. We present results based on five years of observations and report the short-term variability of five family members and seven candidates. The mean rotational periods, from Maxwellian fits to the frequency distributions, are 6.27 ± 1.19 hr for the confirmed family members, 6.44 ± 1.16 hr for the candidates, and 7.65 ± 0.54 hr for other TNOs (without relation to the family). According to our study, there is a possibility that Haumea family members rotate faster than other TNOs; however, the sample of family members is still too limited for a secure conclusion. We also highlight the fast rotation of 2002 GH<SUB>32</SUB>. This object has a 0.36 ± 0.02 mag amplitude lightcurve and a rotational period of about 3.98 hr. Assuming 2002 GH<SUB>32</SUB> is a triaxial object in hydrostatic equilibrium, we derive a lower limit to the density of 2.56 g cm<SUP>−3</SUP>. This density is similar to Haumea’s and much more dense than other small TNO densities.
Database: 
ADS
SCOPUS
WOK
URL: 
https://ui.adsabs.harvard.edu/#abs/2016AJ....151..148T/abstract
ADS Bibcode: 
2016AJ....151..148T
Keywords: 
Kuiper belt: general;Kuiper belt objects: individual: Haumea;techniques: photometric;Astrophysics - Earth and Planetary Astrophysics