2005 TN53

2005 TN₅₃ is an inclined Neptune trojan leading Neptune's orbit in the outer Solar System, approximately 80 kilometers in diameter. It was first observed on 7 October 2005, by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory in the Atacama desert of Chile.^[2][3] It was the third such body to be discovered, and the first with a significant orbital inclination, which showed that the population as a whole is very dynamically excited.

2005 TN₅₃

Discovery[1][2][3]
Discovered by	C. Trujillo S. S. Sheppard
Discovery site	Las Campanas Obs.
Discovery date	7 October 2005 (discovery: first observation only)
Designations
MPC designation	2005 TN53
Minor planet category	Neptune trojan L4[4] centaur[1] distant[2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 4
Observation arc	8.00 yr (2,921 days)
Aphelion	31.940 AU
Perihelion	28.088 AU
Semi-major axis	30.014 AU
Eccentricity	0.0642
Orbital period (sidereal)	164.43 yr (60,059 days)
Mean anomaly	301.81°
Mean motion	0° 0m 21.6s / day
Inclination	25.044°
Longitude of ascending node	9.3277°
Argument of perihelion	90.167°
Physical characteristics
Dimensions	68 km (est. at 0.10)[5] 80 km[6]
Apparent magnitude	23.7[6]
Absolute magnitude (H)	9.0[1]

Orbit and classification

Neptune trojans are resonant trans-Neptunian objects (TNO) in a 1:1 mean-motion orbital resonance with Neptune. These Trojans have a semi-major axis and an orbital period very similar to Neptune's (30.10 AU; 164.8 years).

2005 TN₅₃ belongs to the larger L₄ group, which leads 60° ahead Neptune's orbit. It orbits the Sun with a semi-major axis of 30.014 AU at a distance of 28.1–31.9 AU once every 164 years and 5 months (60,059 days). Its orbit has an eccentricity of 0.06 and an inclination of 25° with respect to the ecliptic.^[1]

It has the same orbital period as Neptune and orbits at the L₄ Lagrangian point about 60° ahead of Neptune.^[4] It has an inclination of 25 degrees.^[1][4]

Physical characteristics

Diameter

The discoverers estimate that 2005 TN₅₃ has a mean-diameter of 80 kilometers based on a magnitude of 23.7.^[6] Based on a generic magnitude-to-diameter conversion, it measures approximately 68 kilometers in diameter using an absolute magnitude of 9.0 and an assumed albedo of 0.10.^[5]

Numbering and naming

Due to its orbital uncertainty, this minor planet has not been numbered and its official discoverers have not been determined.^[1][2] If named, it will follow the naming scheme already established with 385571 Otrera, which is to name these objects after figures related to the Amazons, an all-female warrior tribe that fought in the Trojan War on the side of the Trojans against the Greek.^[7]