279 Thule

Orbital diagram
Discovery
Discovered by	Johann Palisa
Discovery date	25 October 1888
Designations
MPC designation	(279) Thule
Pronunciation	/ˈθjuːliː/[1]
Alternative designations	A888 UA, 1920 GA 1923 RA, 1927 EC 1954 FF[2]
Minor planet category	Asteroid belt (Thule)
Adjectives	Thulean /ˈθjuːliən/[3]
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	125.34 yr (45780 d)
Aphelion	4.4617880 AU (667.47398 Gm)
Perihelion	4.2367660 AU (633.81117 Gm)
Semi-major axis	4.3492770 AU (650.64258 Gm)
Eccentricity	0.025869
Orbital period (sidereal)	9.07 yr (3313.0 d)
Mean anomaly	62.75874°
Mean motion	0° 6m 31.184s / day
Inclination	2.323774°
Longitude of ascending node	72.46791°
Argument of perihelion	42.36797°
Physical characteristics
Dimensions	126.59±3.7 km (IRAS)[2]
Synodic rotation period	23.896 h (0.9957 d)[2]
Geometric albedo	0.0412±0.003[2]
Temperature	133 K
Spectral type	B−V=0.75[2] U−B=0.32[2] D (Tholen)[2] X (SMASSII)[2]
Absolute magnitude (H)	8.57[2]

Thule, minor planet designation: 279 Thule, is a large asteroid from the outer asteroid belt. It is classified as a D-type asteroid and is probably composed of organic-rich silicates, carbon and anhydrous silicates. Thule was the first asteroid discovered with a semi-major axis greater than 4 AU. It was discovered by Johann Palisa on 25 October 1888 in Vienna and was named after the ultimate northern land of Thule.

Thule asteroids

Thule was the first discovered member of the Thule dynamical group, which as of 2008 is known to consist of three objects: 279 Thule, (186024) 2001 QG207, and (185290) 2006 UB219.^[4] The orbits of these bodies are unusual. They orbit in the outermost edge of the asteroid belt in a 4:3 orbital resonance with Jupiter, the result of the periodic force Jupiter exerts on a body with Thule's orbital period, in the same way (though with the reverse effect) as the Kirkwood gaps in the more inner parts of the asteroid belt.