The Hubble classification.
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Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance.Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1936.he divided the galaxies into 1) elliptical galaxies2)Spiral galaxies3)Lenticular galaxiesSource:wikipedia
they usually use super computers
astronomers did
Perhaps in the future astronomers will do all the redshifts of the 100 billion galaxies in the universe.
They do not use units: they use the fact that stars are not galaxies. For example, you don't use units to measure the difference between children and countries.
Hubble's galaxy classification diagram, often referred to as the "tuning fork," categorizes galaxies into three main types: elliptical, spiral, and irregular. The diagram resembles a fork, with elliptical galaxies on the left, spirals on the right, and irregular galaxies branching off below. Spiral galaxies are further divided into subcategories based on their structure, with "normal" and "barred" spirals. This classification helps astronomers understand the characteristics and evolutionary pathways of different galaxy types.
That the galaxy is moving away from us.
Astronomers refer to a galaxy with a jumbled scattering of stars as an "irregular galaxy." These galaxies lack a defined shape or structure, distinguishing them from spiral or elliptical galaxies. Irregular galaxies often contain young stars, gas, and dust, and they can be the result of gravitational interactions or collisions with other galaxies.
It is possible that someday astronomers will measure all the distances of the 100 billion galaxies in the universe.
most of the mass in a cluster of galaxies is invisible, which provides astronomers with the strongest evidence that the universe contains a great amount of DARK MATTER
most of the mass in a cluster of galaxies is invisible, which provides astronomers with the strongest evidence that the universe contains a great amount of DARK MATTER
Billions. (rounded)