The Unusual Kuiper Belt Object 2003 SQ317

Abstract

We report photometric observations of Kuiper belt object 2013 SQ317 obtained between 2011 August 21 and 2011 November 1 at the 3.58 m New Technology Telescope, La Silla. We obtained a rotational lightcurve for 2013 SQ317 with a large peak-to-peak photometric range 0.85+/-0.05 mag, and a periodicity, P=7.210+/-0.001 hr. We also measure a nearly neutral broadband colour B-R=1.05+/-0.18 mag and a phase function with slope beta=0.95+/-0.41 mag/deg. The large lightcurve range implies an extremely elongated shape for 2013 SQ317, possibly as a single elongated object but most simply explained as a compact binary. If modelled as a compact binary near hydrostatic equilibrium, the bulk density of 2013 SQ317 is near 2670 kg m^(-3). If 2003 SQ317 is instead a single, elongated object, then its equilibrium density is about 860 kg m^(-3). These density estimates become uncertain at the 30% level if we relax the hydrostatic assumption and account for solid, "rubble pile"-type configurations. 2013 SQ317 has been associated with the Haumea family based on its orbital parameters and near-infrared colour; we discuss our findings in this context. If confirmed as a close binary, 2013 SQ317 will be the second object of its kind identified in the Kuiper belt.

8 pages, 10 figures, 4 tables. Submitted to MNRAS

References in corpus (14)

• "TNOs are Cool": A survey of the trans-Neptunian region X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observations
• Densities of Solar System Objects from their Rotational Lightcurves
• The Diverse Solar Phase Curves of Distant Icy Bodies. Part I: Photometric Observations of 18 Trans-Neptunian Objects, 7 Centaurs, and Nereid
• TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of 9 bright targets at 70--500 micron
• The Bimodal Colors of Centaurs and Small Kuiper Belt Objects
• Candidate Members and Age Estimate of the Family of Kuiper Belt Object 2003 EL61
• High Precision Photometry of Extreme KBO 2003 EL61
• Water Ice on the Satellite of Kuiper Belt Object 2003 EL61
• Detection of Additional Members of the 2003 EL61 Family via Infrared Spectroscopy
• The Creation of Haumea's Collisional Family
• The Youthful Appearance of the 2003 EL61 Collisional Family
• Time-Resolved Near-Infrared Photometry of Extreme Kuiper Belt Object Haumea
• The effect of orbital evolution on the Haumea (2003 EL61) collisional family
• Characterisation of candidate members of (136108) Haumea's family: II. Follow-up observations

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