Lightcurves of 20--100 kilometer Kuiper Belt Objects using the Hubble Space Telescope

Abstract

We report high precision photometry of three small and one larger Kuiper Belt Objects (KBOs) obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope (ACS/HST). The three small bodies are the smallest KBOs for which lightcurve measurements are available. 2003 BF91 has a diameter of 20 kilometers (assuming 10% albedo) and a 1.09 magnitude, 9.1-hour lightcurve that is feasibly explained by the rotation of an elongated, coherent body that is supported by material strength and best imagined as an icy outer Solar System analog to asteroid (243) Ida. Two other small KBOs, 2003 BG91 and 2003 BH91 (diameters 31 and 18 km, with albedo 10%), exhibit an unremarkable lightcurve and no detectable photometric variation, respectively. For the larger KBO 2000 FV53 (116 km diameter, assuming 10% albedo) we strongly detect a non-sinusoidal periodic (7.5 hours) brightness variation with a very small amplitude (0.07 mag). This KBO may be nearly spherical, a result that might not be unusual in the Kuiper Belt but would be remarkable among outer Solar System satellites of similar size. We carry out a study of possible physical states and bulk densities under the assumptions of both fluid equilibrium and finite, non-zero internal friction. The densities for the these KBOs are likely to be in the range 1--2 g/cm3, and a plausible solution for 2000 FV53 is a rubble pile of this density that is held slightly out of the minimum-energy shape by internal friction among constituent blocks that are relatively small. Our interpretation of 2000 FV53 as a pulverized but essentially primordial object and 2003 BF91 as a collisional fragment is consistent with models of collisional timescales in the outer Solar System. We compile all published KBO lightcurve data and compare our results to the larger population. [abridged]

arXiv commentAJ, in press. Tables 1-4 will be electronic only in published version but appear here in full. Figures 1,3,5 in color

References in corpus (16)

• The Size Distribution of Trans-Neptunian Bodies
• Shaping the Kuiper belt size spectrum by shattering large but strengthless bodies
• Time-Resolved Photometry of Kuiper Belt Objects: Rotations, Shapes and Phase Functions
• Direct N-body Simulations of Rubble Pile Collisions
• Collision rates in the present-day Kuiper Belt and Centaur Regions: Applications to surface activation and modification on Comets, Kuiper Belt Objects, Centaurs, and Pluto-Charon
• Detection of Six Transneptunian Binaries with NICMOS: A High Fraction of Binaries in the Cold Classical Disk
• Extreme Kuiper Belt Object 2001 QG298 and the Fraction of Contact Binaries
• Thermal Properties of Centaurs Asbolus and Chiron
• Physical Properties of Trans-Neptunian Object (20000) Varuna
• Detection of Two Binary Trans-Neptunian Objects, 1997 CQ29 and 2000 CF105, with the Hubble Space Telescope
• The Orbit, Mass, and Albedo of Transneptunian Binary 1999 RZ253
• The Orbit and Albedo of Transneptunian Binary 1997 CQ29
• On the detectability of lightcurves of Kuiper Belt objects
• Size determination of the Centaur Chariklo from millimeter-wavelength bolometer observations
• On the Rotation Period of (90377) Sedna
• Visible-IR Colors and Lightcurve Analysis of Two Bright TNOs: 1999 TC36 and 1998 SN165

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