Cybele asteroids are a group of asteroid

Asteroid

Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s in the outer main belt with a semi-major axis

Semi-major axis

The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

 between 3.27 AU

Astronomical unit

An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....

 and 3.7 AU, an eccentricity

Orbital eccentricity

The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...

 less than 0.3, and an inclination

Inclination

Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 less than 25°. The group is named for the asteroid 65 Cybele

65 Cybele

65 Cybele is one of the largest asteroids in the Solar System and is located in the outer asteroid belt. It gives its name to the Cybele family of asteroids that orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. Cybele is a C-type asteroid, meaning that it is dark in color...

. As of 2010, the group is thought to have been formed by the breakup of larger object in the distant past.

Some of the largest Cybele asteroids are 87 Sylvia

87 Sylvia

87 Sylvia is one of the largest main-belt asteroids. It is a member of the Cybele group located beyond the core of the belt . Sylvia is remarkable for being the first asteroid known to possess more than one moon....

, 65 Cybele

65 Cybele

65 Cybele is one of the largest asteroids in the Solar System and is located in the outer asteroid belt. It gives its name to the Cybele family of asteroids that orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. Cybele is a C-type asteroid, meaning that it is dark in color...

 (the group's namesake), 107 Camilla

107 Camilla

107 Camilla is one of the largest main-belt asteroids. It orbits within the Cybele Group, beyond most main-belt asteroids. It has a very dark surface and primitive carbonaceous composition. It was discovered by N. R...

, 121 Hermione

121 Hermione

121 Hermione is a very large asteroid of the dark C spectral type, orbiting in the Cybele group in the far outer asteroid belt. As a C-type, it is probably composed of carbonaceous materials. It was discovered in 1872, and it also has small asteroid moon discovered in 2002.-Discovery:Hermione was...

, 76 Freia

76 Freia

76 Freia is a very large main-belt asteroid. It orbits in the outer part of the asteroid belt and is classified as a Cybele asteroid. Its composition is very primitive and it is extremely dark in color. Freia was discovered by the astronomer Heinrich d'Arrest on October 21, 1862, in Copenhagen,...

, 790 Pretoria

790 Pretoria

790 Pretoria is a minor planet orbiting the Sun. It is a member of the Cybele group located beyond the core of the main belt . It is in diameter with a 10.37 hour rotation period.-External links:*...

, and 566 Stereoskopia

566 Stereoskopia

566 Stereoskopia is a minor planet orbiting the Sun. It is a member of the Cybele group located beyond the core of the main belt . It is 168 km in diameter with a 12.1 hour rotation period.-External links:*...

. Some of the group also have asteroid moons, such as 121 Hermione.

See also

• Minor planet groups