An intermediate spiral galaxy is a galaxy that is in between the classifications of a

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies, and generally affect both the motions of stars and interstellar gas within spiral galaxies ...

and an

unbarred spiral galaxy An unbarred spiral galaxyAstronomy Pictures(accessed 18 April 2010) is a type of spiral galaxy without a central bar, or one that is not a barred spiral galaxy. It is designated with an SA in the galaxy morphological classification scheme. Ba ...

. It is designated as SAB in the

galaxy morphological classification Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance. There are several schemes in use by which galaxies can be classified according to their morphologies, the most f ...

system devised by

Gerard de Vaucouleurs Gerard is a masculine forename of Proto-Germanic origin, variations of which exist in many Germanic and Romance languages. Like many other early Germanic names, it is dithematic, consisting of two meaningful constituents put together. In this ca ...

. Subtypes are labeled as SAB0, SABa, SABb, or SABc, following a sequence analogous to the

Hubble sequence The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a t ...

for barred and unbarred spirals. The subtype (0, a, b, or c) is based on the relative prominence of the central

bulge __NOTOC__ Bulge may refer to: Astronomy and geography *Bulge (astronomy), a tightly packed group of stars at the center of a spiral galaxy *Equatorial bulge, a bulge around the equator of a planet due to rotation * Tharsis bulge, vast volcanic pl ...

and how tightly wound the

spiral arms Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''

Examples

References

* Galaxy morphological types {{Spiral-galaxy-stub