Abstract
Images of the Kuiper Belt object (126719) 2002 CC249 obtained in 2016 and 2017 using the 6.5 m Magellan-Baade Telescope and the 4.3 m Discovery Channel Telescope are presented. A light curve with a periodicity of 11.87 +/- 0.01 hr and a peak-to-peak amplitude of 0.79 +/- 0.04 mag is reported. This high amplitude double-peaked light curve can be due to a single elongated body, but it is best explained by a contact binary system from its U-/V-shaped light curve. We present a simple full-width-at-half-maximum test that can be used to determine if an object is likely a contact binary or an elongated object based on its light curve. Considering that 2002 CC249 is in hydrostatic equilibrium, a system with a mass ratio q(min) = 0.6, and a density rho(min) = 1 g cm(-3), or less plausible a system with q(max) = 1, and rho(max) = 5 g cm(-3) can interpret the light curve. Assuming a single Jacobi ellipsoid in hydrostatic equilibrium and an equatorial view, we estimate rho >= 0.34 g cm(-3), and a/b = 2.07. Finally, we report a new color study showing that 2002 CC249 displays an ultra red surface characteristic of a dynamically Cold Classical trans-Neptunian object.