V-type asteroid

The spectra of the V-type asteroids or Vestoids are similar to that of 4 Vesta, by far the largest asteroid in this class (hence the name).

A large proportion have orbital elements similar to those of 4 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 most or all of them originated as fragments of Vesta's crust, possibly blasted out by a single very large impact at some point in its history. The enormous southern-hemisphere crater on Vesta is the prime candidate for the impact site cite journal | author= S. J. Bus and R. P. Binzel| title= "Phase II of the Small Main-belt Asteroid Spectroscopy Survey: A feature-based taxonomy"| journal= Icarus| year= 2002| volume= 158| pages= 146| doi= 10.1006/icar.2002.6856] .

The V-type asteroids are moderately bright, and rather similar to the more common S-type, which are also made up of stony irons and ordinary chondrites. This rather rare type of asteroid contains more pyroxene than the S-type.

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 cite journal | author= R. P. Binzel and S. Xu| title= "Chips off of asteroid 4 Vesta: Evidence for the parent body of basaltic achondrite meteorites"| journal= Science| year= 1993| volume= 260| pages= 186 | doi= 10.1126/science.260.5105.186| pmid= 17807177] , likely being derived from deeper parts of the crust of 4 Vesta.

Distribution

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 [cite journal | author= V. Carruba et al| title= "On the V-type asteroids outside the Vesta family"| journal= Astronomy & Astrophysics| year= 2005| volume= 441| pages= 819| doi= 10.1051/0004-6361:20053355] :
*809 Lundia Orbits within the Flora family region
*956 Elisa
*1459 Magnya Orbits in the outer main belt, too far from Vesta to be genetically related. May be the remains of a different ancient differentiated body that was shattered long ago.
*2113 Ehrdni
*2442 Corbett
*2566 Kirghizia
*2579 Spartacus — contains a significant portion of olivine, which may indicate origin deeper within Vesta than other V-types.
*2640 Hallstrom
*2653 Principia
*2704 Julian Loewe
*2763 Jeans
*2795 Lepage
*2851 Harbin
*2912 Lapalma
*3849 Incidentia
*3850 Peltier Orbits within the Flora family region
*3869 Norton
*4188 Kitezh
*4278 Harvey Member of Baptistina family.
*4434 Nikulin
*4796 Lewis
*4977 Rauthgundis
*5379 Abehiroshi

References