65 Cybele
Encyclopedia
65 Cybele is one of the largest asteroid
s 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 and carbonaceous
in composition. It was discovered in 1861 by Ernst Tempel and named after Cybele
the earth goddess.
in recognition of his achievements in telescope
production. Von Steinheil elected to name it "Maximiliana" after the reigning monarch Maximilian II of Bavaria
. At the time, asteroids were conventionally given classical names, and a number of astronomers protested this contemporary appellation. The name Cybele
was chosen instead, referring to the Phrygian
goddess of the earth.
was observed on October 17, 1979 in the Soviet Union
. The asteroid appeared to have an irregular shape, with the longest chord
being measured as 245 km, closely matching the diameter of 237 km determined by the IRAS
satellite in 1983. During the same 1979 occultation, a hint of a possible 11 km wide satellite
was detected.
In 1985, Green estimated Cybele to have a diameter of 330 km. In 2004, Müller estimated Cybele using thermophysical modelling (TPM) to have dimensions of 302×290×232 km. The diameter from IRAS observations in 1983 are listed on the JPL Small-Body Database as 237.26 km (118.63 km radius) as of 2010.
. This can be explained by the presence of water ice. The asteroid may be covered in a layer of fine silicate dust mixed with small amounts of water-ice and organic solids.
star in the constellation Ophiuchus. On October 11, 2009, Cybele occulted a 13.4 magnitude
star in the constellation Aquarius
.
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 Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
and is located in the outer asteroid belt
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
. It gives its name to the Cybele family of asteroids
Cybele asteroid
Cybele asteroids are a group of asteroids in the outer main belt with a semi-major axis between 3.27 AU and 3.7 AU, an eccentricity less than 0.3, and an inclination less than 25°. The group is named for the asteroid 65 Cybele...
that orbit outward from the Sun from the 2:1 orbital resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
. Cybele is a C-type asteroid
C-type asteroid
C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids, and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type...
, meaning that it is dark in color and carbonaceous
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
in composition. It was discovered in 1861 by Ernst Tempel and named after Cybele
Cybele
Cybele , was a Phrygian form of the Earth Mother or Great Mother. As with Greek Gaia , her Minoan equivalent Rhea and some aspects of Demeter, Cybele embodies the fertile Earth...
the earth goddess.
Discovery and naming
Cybele was discovered on March 8, 1861, by Ernst Tempel from the Marseilles Observatory. A minor controversy arose from its naming process. Tempel had awarded the honour of naming the asteroid to Carl August von SteinheilCarl August von Steinheil
Carl August von Steinheil was a German physicist, inventor, engineer and astronomer.-Biography:Steinheil was born in Ribeauvillé, Alsace. He studied law in Erlangen since 1821, then astronomy in Göttingen and Königsberg. He continued his studies in astronomy and physics when he started living on...
in recognition of his achievements in telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
production. Von Steinheil elected to name it "Maximiliana" after the reigning monarch Maximilian II of Bavaria
Maximilian II of Bavaria
Maximilian II of Bavaria was king of Bavaria from 1848 until 1864. He was son of Ludwig I of Bavaria and Therese of Saxe-Hildburghausen.-Crown Prince:...
. At the time, asteroids were conventionally given classical names, and a number of astronomers protested this contemporary appellation. The name Cybele
Cybele
Cybele , was a Phrygian form of the Earth Mother or Great Mother. As with Greek Gaia , her Minoan equivalent Rhea and some aspects of Demeter, Cybele embodies the fertile Earth...
was chosen instead, referring to the Phrygian
Phrygian
Phrygian can refer to:*A person from Phrygia*Phrygian cap once characteristic of the region* Phrygian language*Phrygian mode in music* Phrygian Valley, a historic location in northwestern Turkey...
goddess of the earth.
Physical characteristics
The first Cybelian stellar occultationOccultation
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy . It can also refer to any situation wherein an object in the foreground blocks from view an object in the background...
was observed on October 17, 1979 in the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
. The asteroid appeared to have an irregular shape, with the longest chord
Chord (astronomy)
In the field of astronomy the term chord typically refers to a line crossing an object which is formed during an occultation event. By taking accurate measurements of the start and end times of the event, in conjunction with the known location of the observer and the object's orbit, the length of...
being measured as 245 km, closely matching the diameter of 237 km determined by the IRAS
IRAS
The Infrared Astronomical Satellite was the first-ever space-based observatory to perform a survey of the entire sky at infrared wavelengths....
satellite in 1983. During the same 1979 occultation, a hint of a possible 11 km wide satellite
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
was detected.
In 1985, Green estimated Cybele to have a diameter of 330 km. In 2004, Müller estimated Cybele using thermophysical modelling (TPM) to have dimensions of 302×290×232 km. The diameter from IRAS observations in 1983 are listed on the JPL Small-Body Database as 237.26 km (118.63 km radius) as of 2010.
Spectrum
Examination of the asteroid's infrared spectrum shows an absorption feature that is similar to the spectrum of 24 Themis24 Themis
24 Themis is one of the largest main-belt asteroids. It is also the largest member of the Themistian asteroid family. It was discovered by Annibale de Gasparis on April 5, 1853...
. This can be explained by the presence of water ice. The asteroid may be covered in a layer of fine silicate dust mixed with small amounts of water-ice and organic solids.
Recent occultations
On August 24, 2008, Cybele occulted 2UCAC 24389317, a 12.7 magnitudeApparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
star in the constellation Ophiuchus. On October 11, 2009, Cybele occulted a 13.4 magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
star in the constellation Aquarius
Aquarius (constellation)
Aquarius is a constellation of the zodiac, situated between Capricornus and Pisces. Its name is Latin for "water-bearer" or "cup-bearer", and its symbol is , a representation of water....
.
External links
- Orbital simulation from JPL (Java) / Ephemeris