You can see why this diagram is called the Hubble tuning fork. Hubble believed that galaxies started at the left end of the diagram and evolved to the right. He called the elliptical galaxies "early galaxies" and the spirals "late galaxies."
What is Hubble's classification of galaxies?
Edwin Hubble invented a classification of galaxies and grouped them into four classes: spirals, barred spirals, ellipticals and irregulars.
What are spiral galaxies classified by?
Spiral galaxies are classified as Sa/SBa, Sb/SBb or Sc/SBc (classic/barred) according to the tightness of their spiral, the clumpiness of their spiral arms, and the size of their central bulge. These differences can be traced back to the relative amounts of gas and dust contained within the galaxies.
How are elliptical galaxies classified?
How are galaxies classified using the Hubble fork diagram?
The Hubble tuning fork is a diagram that astronomer Edwin Hubble created in 1926 to classify galaxies. The Hubble tuning fork divides galaxies into three main categories based on morphology: elliptical galaxies, lenticular galaxies, and spiral galaxies.
How are elliptical galaxies and spiral classified according to hubble
Hubble classified these galaxies by referring to them as SB galaxies with subclasses a, b, and c, just like the normal spirals. The spiral arms in barred