A V-type asteroid
is an asteroid
whose spectral type
is that of 4 Vesta
. Approximately 6% of main-belt asteroids
are vestoids, with Vesta being by far the largest of them. They are relatively bright, and rather similar to the more common S-type asteroid
, which are also made up of stony irons
and ordinary chondrites
, with V-types containing more pyroxene
A large proportion of vestoids have orbital elements similar to those of Vesta, either close enough to be part of the Vesta family, or having similar eccentricities and inclinations but with a semi-major axis lying between about 2.18 AU and the 3:1 Kirkwood gap at 2.50 AU. This suggests that they originated as fragments of Vesta's crust. There seem to be two populations of Vestoids, one created 2 billion years ago and the other 1 billion years ago, coming respectively from the enormous southern-hemisphere craters Veneneia and Rheasilvia. Fragments that ended up in the 3:1 Jupiter resonance were perturbed out of the Kirkwood gap and some fragments eventually hit the earth as HED meteorites.
The electromagnetic spectrum has a very strong absorption feature longward of 0.75 μm, another feature around 1 μm and is very red shortwards of 0.7 µm. The visible wavelength spectrum of the V-type asteroids (including 4 Vesta itself) is similar to the spectra of basaltic achondrite HED meteorites.
A J-type has been suggested for asteroids having a particularly strong 1 μm absorption band similar to diogenite meteorites, likely being derived from deeper parts of the crust of 4 Vesta.
The vast majority of V-type asteroids are members of the Vesta family along with Vesta itself. There are some Mars-crossers such as 9969 Braille, and some Near-Earth objects like 3908 Nyx.
There is also a scattered group of objects in the general vicinity of the Vesta family but not part of it. These include:
This page was last edited on 16 May 2018, at 14:15 (UTC)
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