2008 OG₁₉: A highly elongated Trans-Neptunian Object

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From two observing runs during the 2014 summer at Calar Alto Observatory in Almería (Spain) and at Sierra Nevada Observatory in Granada (Spain), we were able to derive CCD photometry of the Trans-Neptunian Object 2008 OG₁₉. We analyzed the time series and obtained a double-peaked light curve with a peak to valley amplitude of (0.437 ± 0.011) mag and a rotational period of (8.727± 0.003) h. This implies that this object is very elongated, closely resembling Varuna's case. The photometry also allowed us to obtain an absolute magnitude in R-band of (4.39 ± 0.07) mag. From this result we estimated an equivalent diameter of 2008 OG₁₉ which is 619⁺⁵⁶₋₁₁₃ km using an average albedo for Scattered Disk Objects. Finally we interpreted the results under the assumption of hydrostatic equilibrium and found a lower limit for the density of 544⁺⁴²₋₄ kgm⁻³. However, a more likely density is (609 ± 4) kgm⁻³ using an aspect angle of 60∘, which corresponds to the most likely configuration for the spin axis with respect to the observer assuming random orientations.