Density wave theory
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Density wave theory or the Lin–Shu density wave theory is a theory proposed by C.C. Lin and Frank Shu in the mid-1960s to explain the spiral arm structure of spiral galaxies. The Lin–Shu theory introd
Image of spiral galaxy M81 combining data from the Hubble, Spitzer, and GALEX space telescopes.
Spiral density waves in Saturn's A Ring induced by resonances with nearby moons.
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
Density wave theory
…wave theory or the Lin–Shu density wave theory is a theory proposed by C.C. Lin and Frank Shu in the mid-1960s to explain the spiral arm structure of spiral galaxies. The Lin–Shu theory introduces the idea of long-lived quasi-stationary spiral structure (QSSS hypothesis). In this hypothesis, the spiral pattern rotates…
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