T-type asteroids are rare inner-belt
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
s of unknown composition with dark, featureless and moderately
red
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–750 nanometres. It is a primary color in the RGB color model and a seconda ...
spectra, and a moderate absorption feature shortwards of 0.85 μm. No direct
meteorite
A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...
analog has been found to date. Thought to be
anhydrous
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...
, they are considered to be related to
P-types or
D-types, or possibly a highly altered
C-type.
Examples of T-type asteroids include
96 Aegle
96 Aegle is a carbonaceous asteroid and the namesake of the Aegle family located in the outer regions of the asteroid belt, approximately in diameter. It was discovered on 17 February 1868, by French astronomer Jérôme Coggia at the Marseil ...
,
114 Kassandra
114 Kassandra is a large and dark main-belt asteroid. It belongs to the rare class T. It was discovered by C. H. F. Peters on July 23, 1871, and is named after Cassandra, the prophetess in the tales of the Trojan War.
This object is classifi ...
,
233 Asterope
233 Asterope is a large main-belt asteroid that was discovered on 11 May 1883, by French astronomer Alphonse Borrelly at Marseille Observatory in Marseille, France. The asteroid was named after Asterope (or Sterope), one of the Pleiades.
Th ...
, and
308 Polyxo
308 Polyxo is a main-belt asteroid that was discovered by Alphonse Borrelly on 31 March 1891, in Marseille. It is orbiting the Sun at a distance of with a low orbital eccentricity (ovalness) of 0.04 and a period of . The orbital plane is tilt ...
. The infrared spectrum of the first three are similar to the mineral
troilite
Troilite () is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe(1−x)S (x = 0 to 0.2) which is iron deficient. As troilite lacks the iron deficiency ...
, while 308 Polyxo is modified with hydration features.
[
In 2010, the asteroid ]596 Scheila
596 Scheila is a Asteroid belt, main-belt asteroid and main-belt comet
orbiting the Sun. It was discovered on 21 February 1906 by August Kopff from Heidelberg. Kopff named the asteroid after a female English student with whom he was acquainted.
...
was impacted by a projectile. The impact changed its spectrum from T-type to D-type, likely by exposing fresh material that was not weathered
''Weathered'' is the third studio album by American rock band Creed, released on November 20, 2001. It was the last Creed album to be released until '' Full Circle'' came out in October 2009, with Creed disbanding in June 2004. It is the only Cr ...
.
See also
*Asteroid spectral types
An asteroid spectral type is assigned to asteroids based on their reflectance spectrum, color, and sometimes Astronomical albedo, albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not p ...
References
Asteroid spectral classes
*
{{Asteroid-stub