2004 TT357: A potential contact binary in the Trans-Neptunian belt

Abstract

We report photometric observations of the trans-Neptunian object 2004~TT${}_{357}$ obtained in 2015 and 2017 using the 4.3~m Lowell's Discovery Channel Telescope. We derive a rotational period of 7.79$\pm$0.01~h and a peak-to-peak lightcurve amplitude of 0.76$\pm$0.03~mag. 2004 TT${}_{357}$ displays a large variability that can be explained by a very elongated single object or can be due to a contact/close binary. The most likely scenario is that 2004 TT${}_{357}$ is a contact binary. If it is in hydrostatic equilibrium, we find that the lightcurve can be explained by a system with a mass ratio q${}_{min}$=0.45$\pm$0.05, and a density of ${\rho }_{min}$=2g cm${}^{-3}$, or less likely a system with q${}_{max}$=0.8$\pm$0.05, and ${\rho }_{max}$=5g cm${}^{-3}$. Considering a single triaxial ellipsoid in hydrostatic equilibrium, we derive a lower limit to the density of 0.78g cm${}^{-3}$, and an elongation (a/b) of 2.01 assuming an equatorial view. From Hubble Space Telescope data, we report no resolved companion orbiting 2004 TT${}_{357}$. Despite an expected high fraction of contact binaries in the trans-Neptunian belt, 2001 QG${}_{298}$ is the unique confirmed contact binary in the trans-Neptunian belt, and 2004 TT${}_{357}$ is only the second candidate to this class of systems, with 2003 SQ${}_{317}$.

arXiv commentIn Press, ApJ

References in corpus (17)

• "TNOs are Cool": A survey of the trans-Neptunian region X. Analysis of classical Kuiper belt objects from Herschel and Spitzer observations
• Extreme Kuiper Belt Object 2001 QG298 and the Fraction of Contact Binaries
• Characterization of Seven Ultra-Wide Trans-Neptunian Binaries
• An Automatic Method for Extreme-Ultraviolet Dimmings Associated with Small-Scale Eruption
• Short-term variability of a sample of 29 trans-Neptunian objects and Centaurs
• The density of mid-sized Kuiper belt object 2002 UX25 and the formation of the dwarf planets
• High Precision Photometry of Extreme KBO 2003 EL61
• The Color Differences of Kuiper Belt Objects in Resonance with Neptune
• Rotational properties of the binary and non-binary populations in the Trans-Neptunian belt
• Fraction of Contact Binary Trojan Asteroids
• Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam
• A Change in the Lightcurve of Kuiper Belt Contact Binary (139775) 2001 QG298
• 2007 TY430: A Cold Classical Kuiper Belt Type Binary in the Plutino Population
• Short-term variability of 10 trans-Neptunian objects
• The Unusual Kuiper Belt Object 2003 SQ317
• Rotational properties of the Haumea family members and candidates: Short-term variability
• Binary Candidates in the Jovian Trojan and Hilda Populations from NEOWISE Lightcurves

Cited by in corpus (12)

• The Plutino population: An Abundance of contact binaries
• Trans-Neptunian binaries (2018)
• Lightcurves and Rotational Properties of the Pristine Cold Classical Kuiper Belt Objects
• Constraints on the Density and Internal Strength of 1I/'Oumuamua
• A Statistical Review of Light Curves and the Prevalence of Contact Binaries in the Kuiper Belt
• A possible dynamically Cold Classical contact binary: (126719) 2002 CC249
• Great Expectations: Plans and Predictions for New Horizons Encounter with Kuiper Belt Object 2014 MU69 ('Ultima Thule')
• Colors of Trans-Neptunian Contact Binaries
• OSSOS XII: Variability studies of 65 Trans-Neptunian Objects using the Hyper Suprime-Cam
• The changing rotational light-curve amplitude of Varuna and evidence for a close-in satellite
• Direct contact binary planetesimal formation from gravitational collapse
• The shape and spin state of (275677) 2000 RS11 from ground-based radar and optical observations