Astronomers have concluded that the easiest way to identify galaxies is through observation of their visual features. Galaxies are formed when billions of stars dust and gas particles come together. They are held together by the force of gravity. These components combine to form different distinctive shapes which are used to classify galaxies. The commonly used method is the morphology classification. This has been made easier by the current computation methods. The following are properties used to group galaxies.
Galaxies come in different shapes. The shape is influenced by the force of gravity, holding the particles together. Other bodies surrounding the universe also have the power of gravity that affects it. The spinning speed also influences the shape of galaxies. Spiral galaxies have a matter that is in a spiral shape, which is controlled by its speed. Elliptical galaxies have an extensive spherical shape. There are also Irregular galaxies with no definite form.
Type of Stars
Different types of galaxies have different stars. There are bright and dimmer stars. There are also old and younger stars. The type of stars contributes to the brightness of the galaxy. Young bright stars are dominant in Spiral galaxies and some parts of Elliptical galaxies. The largest part of Elliptical galaxies is dominated by old red stars.
Some galaxies possess a nuclear and protuberance at the central region. Galaxies with nuclei are Spiral galaxies and Barred Spiral galaxies. Irregular galaxies and Elliptical galaxies do not have any core.
These distinctive properties have resulted in four main groups of galaxies; Irregular galaxies, Elliptical galaxies, Spiral galaxies and Barred Spiral galaxies. There are also other minor types of galaxies. Astronomers have continued with more discoveries of more galaxies. This means that there is a need to continue with research to have the latest updates.