|Discovered by||D. C. Jewitt|
J. X. Luu
C. A. Trujillo
|Discovery site||Mauna Kea Obs.|
|Discovery date||9 October 1996|
|MPC designation||(15874) 1996 TL66|
|TNO  · SDO|
|Epoch 13 January 2016 (JD 2457400.5)|
|Uncertainty parameter 2|
|Observation arc||5883 days (16.11 yr)|
|Aphelion||131.75 AU (19.710 Tm)|
|Perihelion||35.057 AU (5.2445 Tm)|
|83.403 AU (12.4769 Tm)|
|761.70 yr (278211 d)|
|0° 0m 4.658s / day|
|12 h (0.50 d)|
|B–V = 0.687±0.072|
V–R = 0.369±0.052
The Spitzer Space Telescope has estimated this object to be about 575 kilometres (357 mi) in diameter, but 2012 estimates from the Herschel Space Observatory estimate the diameter as closer to 339 kilometres (211 mi). 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 (15874) 1996 TL66 is very probably a dwarf planet. Mike Brown's website, using a radiometrically determined diameter of 344 kilometres (214 mi), lists it as a possible dwarf planet.
Discovered in 1996 by David C. Jewitt et al., it was the first object to be categorized as a scattered-disk object (SDO), although (48639) 1995 TL8, discovered a year earlier, was later recognised as a scattered-disk object. It was one of the largest known trans-Neptunian objects at the time of the discovery. It came to perihelion in 2001.
(15874) 1996 TL66 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 575±115 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 339±20 km. Light-curve-amplitude analysis shows only small deviations, suggesting (15874) 1996 TL66 is a spheroid with small albedo spots and may be a dwarf planet.