<P> An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy . Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure . </P> <P> Collectively they are thought to make up about a quarter of all galaxies . Some irregular galaxies were once spiral or elliptical galaxies but were deformed by an uneven external gravitational force . Irregular galaxies may contain abundant amounts of gas and dust . This is not necessarily true for dwarf irregulars . </P>

How many stars are in the irregular galaxy