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 second-most common after the carbonaceousC-type.
S-type asteroids, with an astronomical albedo of typically 0.20,[1] are moderately bright and consist mainly of iron- and magnesium-silicates. They are dominant in the inner part of the asteroid belt within 2.2 AU, common in the central belt within about 3 AU, but become rare farther out. The largest are 3 Juno (about 240–250 km across) and 15 Eunomia (230 km), with other large S-types being 29 Amphitrite, 532 Herculina and 7 Iris. These largest S-types are visible in 10x50 binoculars at most oppositions; the brightest, 7 Iris, can occasionally become brighter than +7.0, which is a higher magnitude than any asteroid except the unusually reflective 4 Vesta.
Their spectrum has a moderately steep slope at wavelengths shorter than 0.7 micrometres (μm), and has moderate to weak absorption features around 1 μm and 2 μm. The 1 μm absorption is indicative of the presence of silicates (stony minerals). Often there is also a broad but shallow absorption feature centered near 0.63 μm. The composition of these asteroids is similar to a variety of stony meteorites which share similar spectral characteristics.
Due to their volatile-poor (rocky) composition, S-type asteroids have relatively high density. A survey of 11 S-type asteroids found an average density of 3.0 g/cm3.[2]
S-group asteroidsedit
SMASS classificationedit
In the SMASS classification, several generally "stony" types of asteroids are brought together into a wider S-group which contains the following types:
a "core" S-type for asteroids having the most typical spectra for the S-group
Sa, Sk, Sl, Sq, and Sr-types containing transition objects between the core S-type and the A, K, L, Q, and R-types, respectively. The entire "S"-assemblage of asteroids is spectrally quite distinct from the carbonaceous C-group and the often metallic X-group.
Tholen classificationedit
In the Tholen classification, the S-type is a very broad grouping which includes all the types in the SMASS S-group except for the A, Q, and R, which have particularly strong "stony" absorption features around 1 μm.
^ ab. LCDB. Archived from the original on 16 November 2015. Retrieved 16 February 2018.
^P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
Bus, S. J.; Binzel, R. P. (2002). "Phase II of the Small Main-belt Asteroid Spectroscopy Survey: A feature-based taxonomy". Icarus. 158 (1): 146–177. Bibcode:2002Icar..158..146B. doi:10.1006/icar.2002.6856. S2CID 4880578.
April 16, 2024
type, asteroid, asteroids, with, spectral, type, that, indicative, siliceous, stony, mineralogical, composition, hence, name, they, have, relatively, high, density, approximately, asteroids, this, type, making, second, most, common, after, carbonaceous, type, . 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 second most common after the carbonaceous C type 433 Eros an example of an S type asteroid Contents 1 Characteristics 2 S group asteroids 2 1 SMASS classification 2 2 Tholen classification 2 3 Stony asteroid families 3 See also 4 ReferencesCharacteristics editS type asteroids with an astronomical albedo of typically 0 20 1 are moderately bright and consist mainly of iron and magnesium silicates They are dominant in the inner part of the asteroid belt within 2 2 AU common in the central belt within about 3 AU but become rare farther out The largest are 3 Juno about 240 250 km across and 15 Eunomia 230 km with other large S types being 29 Amphitrite 532 Herculina and 7 Iris These largest S types are visible in 10x50 binoculars at most oppositions the brightest 7 Iris can occasionally become brighter than 7 0 which is a higher magnitude than any asteroid except the unusually reflective 4 Vesta Their spectrum has a moderately steep slope at wavelengths shorter than 0 7 micrometres mm and has moderate to weak absorption features around 1 mm and 2 mm The 1 mm absorption is indicative of the presence of silicates stony minerals Often there is also a broad but shallow absorption feature centered near 0 63 mm The composition of these asteroids is similar to a variety of stony meteorites which share similar spectral characteristics Due to their volatile poor rocky composition S type asteroids have relatively high density A survey of 11 S type asteroids found an average density of 3 0 g cm3 2 S group asteroids editSMASS classification edit In the SMASS classification several generally stony types of asteroids are brought together into a wider S group which contains the following types A type K type L type Q type R type a core S type for asteroids having the most typical spectra for the S group Sa Sk Sl Sq and Sr types containing transition objects between the core S type and the A K L Q and R types respectively The entire S assemblage of asteroids is spectrally quite distinct from the carbonaceous C group and the often metallic X group Tholen classification edit In the Tholen classification the S type is a very broad grouping which includes all the types in the SMASS S group except for the A Q and R which have particularly strong stony absorption features around 1 mm Stony asteroid families edit Further information Asteroid family All families Prominent stony asteroid families with their typical albedo are the 1 Eos family 0 14 Eunomia family 0 21 Flora family 0 24 Koronis family 0 24 Nysa family 0 20 Phocaea family 0 23 See also editAsteroid spectral types X type asteroidReferences edit a b Asteroid Lightcurve Database README 2 Taxonomic Class orbital class and albedo LCDB Archived from the original on 16 November 2015 Retrieved 16 February 2018 P Vernazza et al 2021 VLT SPHERE imaging survey of the largest main belt asteroids Final results and synthesis Astronomy amp Astrophysics 54 A56 Bus S J Binzel R P 2002 Phase II of the Small Main belt Asteroid Spectroscopy Survey A feature based taxonomy Icarus 158 1 146 177 Bibcode 2002Icar 158 146B doi 10 1006 icar 2002 6856 S2CID 4880578 Retrieved from https en wikipedia org w index php title S type asteroid amp oldid 1182061542, wikipedia, wiki, book, books, library,
