What is galaxy? »Its definition and meaning

It is a conglomeration of planets, millions of stars, dark meteria, clouds formed of gas, cosmic dust and energy that are united thanks to the force of gravity, in addition to this, these elements are orbiting around a point where It is believed that a black hole may exist, the number of stellar elements that make up a specific galaxy is uncountable regardless of its size, other elements that make it up are multiple star systems, nebulae and star clusters.

All those stellar bodies (including the Sun) that can be observed in a simple way from anywhere on the face of the Earth, belong to the so-called Milky Way, according to experts, it has a size of 1012 solar masses with a spiral shape, its diameter is of an approximate size of 1.42 × 1018 kilometers and the number of stars that make it up exceeds 200 billion, the milky way in turn is part of a set of galaxies which are called the Local Group.

Galaxies can have different shapes, including lenticular, elliptical, irregular and spiral.

Lenticular galaxies: these are considered as a kind of transformation between spiral-shaped and elliptical galaxies, they are made up of a large envelope, a disk and a central condensation of great relevance, this type of galaxy is made up of three subcategories, SO1, SO2, SO3.

Elliptical Galaxies: so called because their shape is similar to that of an ellipse, they are classified from 0 to 7, with the number seven being the most oval shape possible, they have little stellar matter and therefore few open clusters, that is why their capacity to produce stars is very low.
Irregular galaxies: as they do not have an elliptical or spiral shape, they do not fall into the Hubble classification, which is why they are called irregular, they are subdivided into two types, Irr-I, which have a structure not clear enough to enter the Hubble classification Another type is the Irr-II, unlike the first, they do not have any form that can enter the classification.