K-type asteroids are relatively uncommon
asteroids with a moderately reddish spectrum shortwards of 0.75 μm, and a slight bluish trend longwards of this. They have a low
albedo
Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...
. Their spectrum resembles that of
CV and CO meteorites. A larger K type is
9 Metis
Metis (minor planet designation: 9 Metis) is one of the larger main-belt asteroids. It is composed of silicates and metallic nickel-iron, and may be the core remnant of a large asteroid that was destroyed by an ancient collision. Metis is esti ...
.
These asteroids were described as "featureless"
S-types in the
Tholen classification
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ...
. The K-type was proposed by J. F. Bell and colleagues in 1988 for bodies having a particularly shallow 1 μm absorption feature, and lacking the 2 μm absorption. These were found during studies of the
Eos family of asteroids.
See also
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Asteroid spectral types
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ...
*
L-type asteroid
L-type asteroids are relatively uncommon asteroids with a strongly reddish spectrum shortwards of 0.75 μm, and a featureless flat spectrum longwards of this. In comparison with the K-type, they exhibit a more reddish spectrum at visible wavele ...
*
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...
*
X-type asteroid The X-group of asteroids collects together several types with similar spectra, but probably quite different compositions.
Tholen classification
In the Tholen classification the X-group consists of the following types:
* E-type – with high al ...
*
181 Eucharis
*
221 Eos
*
402 Chloë
*
417 Suevia
References
J. F. Bell ''A probable asteroidal parent body for the CV and CO chondrites'' Meteoritics, Vol. 23, pp. 256 (1988).
J. F. Bell et al. ''The 52-color asteroid survey: Final results and interpretation'' Lunar and Planetary Science, Vol. 19, pp. 57 (1988).
Asteroid spectral classes
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