Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance, shape, structure, and distribution of light. There are several sche
Spiral galaxy UGC 12591 is classified as an S0/Sa galaxy.
The Hubble sequence throughout the universe's history
NGC 6782: a spiral galaxy (type SB(r)0/a) with three rings of different radii, as well as a bar
NGC 7793: a spiral galaxy of type SA(s)d
Spiral galaxy
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Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae and, as such, form part of the Hubble sequence. Most spiral galaxies consist of a
Galaxy morphological classification
…integer n representing their degree of ellipticity on the sky. The specific ellipticity rating depends on ratio of the major (a) to minor axes (b), thus: Spiral galaxies consist of a flattened disk, with stars forming a (usually two-armed) spiral structure, and a central concentration of stars known as the bulge, which…
An example of a spiral galaxy, Messier 77 (also known as NGC 1068)
Tuning-fork-style diagram of the Hubble sequence
Barred spiral galaxy UGC 12158
NGC 1300 in infrared light