(15874) 1996 TL66

(15874) 1996 TL₆₆ (provisional designation 1996 TL₆₆) is a trans-Neptunian object of the scattered disc orbiting in the outermost region of the Solar System.^[2][3]

(15874) 1996 TL₆₆

Discovery[1]
Discovered by	D. C. Jewitt J. X. Luu J. Chen C. A. Trujillo
Discovery site	Mauna Kea Obs.
Discovery date	9 October 1996
Designations
MPC designation	(15874) 1996 TL66
Alternative designations	1996 TL66
Minor planet category	TNO[2] · SDO[3] distant[4]
Orbital characteristics[2]
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)
Semi-major axis	83.403 AU (12.4769 Tm)
Eccentricity	0.57967
Orbital period (sidereal)	761.70 yr (278211 d)
Mean anomaly	6.8505°
Mean motion	0° 0m 4.658s / day
Inclination	24.006°
Longitude of ascending node	217.82°
Argument of perihelion	184.79°
Physical characteristics
Mean diameter	339±20 km[5] 575±115 km[6]
Synodic rotation period	12 h (0.50 d)[2]
Geometric albedo	0.110+0.021 −0.015[5] 0.035+0.02 −0.01[6]
Spectral type	B–V = 0.687±0.072[7] V–R = 0.369±0.052[7]
Apparent magnitude	21[8]
Absolute magnitude (H)	5.4[2]

The Spitzer Space Telescope has estimated this object to be about 575 kilometres (357 mi) in diameter,^[6] but 2012 estimates from the Herschel Space Observatory estimate the diameter as closer to 339 kilometres (211 mi).^[5] It is not a detached object, since its perihelion (closest approach to the Sun) is under the influence of Neptune.^[3] Light-curve-amplitude analysis suggests that it is a spheroid.^[9]

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 (48639) 1995 TL8, 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.^[10] It came to perihelion in 2001.^[2]

Orbit and size

1996 TL₆₆'s orbit

(15874) 1996 TL₆₆ orbits the Sun with a semi-major axis of 83.9 AU^[2] but is currently only 35 AU from the Sun with an apparent magnitude of 21.^[8] In 2007, the Spitzer Space Telescope estimated it to have a low albedo with a diameter of about 575±115 km.^[6] 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.^[5] 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 has a spheroidal shape with small albedo spots.^[9] It was considered a possible dwarf planet by Gonzalo Tancredi.^[9]