Astronomical object

Astronomical objects such as stars, planets, nebulae, asteroids and comets have been observed for thousands of years, although early cultures thought of these bodies as gods or deities.

These early cultures found the movements of the bodies very important as they used these objects to help navigate over long distances, tell between the seasons, and to determine when to plant crops.

In Europe, astronomers focused more on devices to help study the celestial objects and creating textbooks, guides, and universities to teach people more about astronomy.

This model described the Earth, along with all of the other planets as being astronomical bodies which orbited the Sun located in the center of the Solar System.

In the 19th and 20th century, new technologies and scientific innovations allowed scientists to greatly expand their understanding of astronomy and astronomical objects.

A refined scheme for stellar classification was published in 1943 by William Wilson Morgan and Philip Childs Keenan based on the Hertzsprung-Russel Diagram.

Galaxies are organized into groups and clusters, often within larger superclusters, that are strung along great filaments between nearly empty voids, forming a web that spans the observable universe.

[5] The constituents of a galaxy are formed out of gaseous matter that assembles through gravitational self-attraction in a hierarchical manner.

[6] The great variety of stellar forms are determined almost entirely by the mass, composition and evolutionary state of these stars.

An example of this is the instability strip, a region of the H-R diagram that includes Delta Scuti, RR Lyrae and Cepheid variables.

Some SSSBs are just collections of relatively small rocks that are weakly held next to each other by gravity but are not actually fused into a single big bedrock.