22 Kalliope

22 Kalliope is a big main belt asteroid of the M-type, found by J. R. Hind on November 16, 1852. It is named after Calliope, the Greek Muse of epic poetry.

 Characteristics 
Kalliope is about 180 km in diameter but is not perfectly round, as shown by images from the VLT at the European Southern Observatory synthesis of several observations including recent ones with the VLT 8m telescope.

Its spectrum is M-type, but Kalliope does not appear to be metallic. It is similar to other M-types such as 21 Lutetia. Firstly, its density is far too low to be metal. Second, spectroscopic studies have shown evidence of hydrated minerals  and silicates, so the surface is probably stony. Kalliope also has a low radar albedo, unlike most metallic surfaces.

Lightcurve analysis indicates that Kalliope's pole most likely points towards ecliptic coordinates (β, λ) = (-23°, 20°) with a 10° uncertainty, which gives Kalliope an axial tilt of 103°. Kalliope's rotation is then a bit retrograde.

 Moon 
Kalliope has one known moon, Linus, or (22) Kalliope I Linus. It is quite big: 30–40 km in diameter. It orbits about 1065 km from Kalliope. This is about 12 times the radius of Kalliope. Linus was found on August 29, 2001 by Jean-Luc Margot and Michael E. Brown, while another team also independently found the moon 3 days later.

 References 

 Other websites 
 Kalliope and Linus very well resolved with the 8m VLT at ESO. Also includes a Kalliope shape model.
 shape model deduced from lightcurve 
 orbit diagram for Linus 
 A different VLT image of Kalliope and Linus 
 Data sheet at Johnston's Archive, includes some other parameters.

Category:Asteroids