Elliptical galaxies are generally circular in shape and are often elongated. Most galaxies in the universe are either elliptical or spiral. The Sombrero galaxy is composed of massive dust clouds, and a bright centre core, which is composed of millions of young stars. In 3D space the Sombrero galaxy has a flat, stretched out shape, with a bulging core that is surrounded by dark dust clouds.
Spiral galaxies are defined as spirals, because they have spiral arms. The galaxy NGC 4603 contains several spiral arms, immersed with dust clouds, which absorb the light pulsating from the stars within it. NGC 4603 is a distant galaxy, which contains a special class of pulsating stars called Cepheid. NGC4603 is also associated with other large collections of galaxies in the Centaurus cluster.
There are approximately 3% of galaxies, which cannot be classified as elliptical or spiral. Often they are distorted and have no rotational symmetry. These types of galaxies are often formed when galaxies collide or when the galaxy is very young and has yet to reach a symmetrical shape. NCG 4242 has an intense bulging nucleus and surrounding gas. As you move further away from the centre, the brightness of the galaxy decreases. Although NGC 4242 appears bright blue in colour, the images of NGC 4242 are often artificially coloured when reproduced for visual impact. The nucleus is most likely at the centre of the galaxy, and made up of a cluster of young stars. Individual (possibly older) bright stars outside of the nucleus are also part of the galaxy and are positioned on the centre plane. The images show a front-on view of the galaxy, but it is possible that it would appear somewhat flat from side on.