90 Antiope - Definition and Overview

90 Antiope

Orbital characteristics 1 (ftp://ftp.lowell.edu/pub/elgb/astorb.html)
Orbit type	Main belt (Themis)
Semimajor axis	3.157 AU
Perihelion distance	2.665 AU
Aphelion distance	3.649 AU
Orbital period	5.61 years
Inclination	2.22°
Eccentricity	0.156
Physical characteristics
Diameter 3 (http://www.johnstonsarchive.net/astro/astmoons/am-00090.html)	85, 85 km
Rotation period 3 (http://www.johnstonsarchive.net/astro/astmoons/am-00090.html)	16.496 hours (sync.)
Spectral class 1 (ftp://ftp.lowell.edu/pub/elgb/astorb.html)	C
Abs. magnitude 1 (ftp://ftp.lowell.edu/pub/elgb/astorb.html)	8.27
Albedo 4 (http://dorothy.as.arizona.edu/DSN/IRAS/index_iras.html)	0.060
History 2 (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html)
Discoverer	R. Luther, 1866
Satellites
Designation	S/2000 (90) 1

90 Antiope is an asteroid discovered on October 1, 1866 by Robert Luther. The 90th asteroid to be discovered, it is named after a character in Greek Mythology, called Antiope, though it is disputed as to which, there being more than one.

Antiope is classified as a member of the Themis family of asteroids.

One observed stellar occultation by Antiope has been reported, on (June 11, 1980).

In 2000, it was discovered that Antiope is a double asteroid, consisting of two individual bodies about 80 kilometers across and separated by 170 kilometers, orbiting around a common center. A complete revolution takes 16.5 hours. Their composition is C-type, which means that they are dark in colouring with a carbonate composition.

The discovery was made with the Keck Telescope at Mauna Kea using adaptive optics, allowing the two components to be resolved.

External links

• SWrI Press Release (http://www.boulder.swri.edu/merline/press/index.html)
• Data from Johnston's Archive (http://www.johnstonsarchive.net/astro/astmoons/am-00090.html)