(15874) 1996 TL66

' (provisional designation ') is a trans-Neptunian object of the scattered disc orbiting in the outermost region of the Solar System.

The Spitzer Space Telescope has estimated this object to be about 575 km in diameter, but 2012 estimates from the Herschel Space Observatory estimate the diameter as closer to 339 km. It is not a detached object, since its perihelion (closest approach to the Sun) is under the influence of Neptune. Light-curve-amplitude analysis suggests that it is a spheroid. Tancredi presents "in the form of a decision tree, the set of questions to be considered in order to classify an object as an icy 'dwarf planet'." They find that is very probably a dwarf planet. Mike Brown's website, using a radiometrically determined diameter of 344 km, lists it as a possible dwarf planet.

Discovery
Discovered in 1996 by David C. Jewitt et al., it was the first object to be categorized as a scattered-disk object (SDO), although, discovered a year earlier, was later recognised as a scattered-disk object. It was considered one the largest known trans-Neptunian objects at the time of the discovery, being placed second after Pluto. It came to perihelion in 2001.

Orbit and size


orbits the Sun with a semi-major axis of 83.9 AU but is currently only 35 AU from the Sun with an apparent magnitude of 21. In 2007, the Spitzer Space Telescope estimated it to have a low albedo with a diameter of about $339 km$. More-recent measurements in 2012 by the 'TNOs are Cool' research project and reanalysis of older data have resulted in a new estimate of these figures. It is now assumed that it has a higher albedo and the diameter was revised downward to $575 km$. Light-curve-amplitude analysis shows only small deviations, suggesting is a spheroid with small albedo spots and may be a dwarf planet.