Constellations | Galaxy | Types Of Constellations | Clusters Types


Human curiosity! A few centuries ago, due to this curiosity, humans turned their attention to the celestial lights that decorate the night sky and began the study of astronomy. Gradually, the cycle of stardom unfolded. Realizing that the stars do not change position relative to each other during this rising cycle, constellations began to be formed by connecting the surrounding stars with imaginary lines. 


In the stars of Mriga Nakshatra, where the Indians imagined a deer wounded by an arrow, the Greeks saw a hunter in the same stars. The speculation behind this was to solve the question of ‘which part of the sky are we looking at, when will the stars be seen in which part’? At present, the entire sky is divided into 88 constellations and the boundaries of each constellation are determined. Actually, constellations are just an idea and different stars in the same constellation are unrelated. It is only because of the same vision that you see them close to each other. Apart from these constellations, there are some groups of stars whose elements appear to be related to each other. Compared to the constellations, these groups are very small in size that we can see. In today’s article, we will learn about such star clusters.

Our galaxy is estimated to have more than 1000 crore stars. A galaxy has a higher number of stars towards its center and a lower number of stars in its spiral arms. Our solar system is located in the Deer-Sagittarius spiral arm and is about 27,000 light-years from the center. The space between the two adjacent spiral arms of the Milky Way has a relatively low density of stars. But there are some places where the star’s density is strongly felt to increase suddenly over the surrounding density. Interestingly, such stations are also found in the spiral arms and up and down from the main galaxy. Areas, where a relatively large number of stars are contained in a small space due to their mutual gravitation, are called star clusters.There are mainly two types of constellations.

Types of Star Clusters

Open Clusters

They do not have a specific shape. Although the density of stars here is higher than in the surrounding area, stars in open clusters can usually be seen individually. A good example of an open constellation is Krittika Nakshatra (Pleiades). During the month of November, one can see the creation throughout the night. 6 stars can be clearly seen in Krittik with the naked eye, while through a telescope one can see a picturesque view of the sky filled with hundreds of stars.

Globular Cluster

It has the appearance of a dense mass of thousands of stars in a small space. Due to the huge crowd of stars, it is difficult to see and study each star independently. Some globular clusters contain more than a million stars. Also, most stars can be over 10 billion years old. That is, since it was born only a few million years after the creation of the universe, it contains only the elements hydrogen and helium (the only elements believed to have existed after the creation of the universe). The gravitational pull between the stars in a globular cluster is so strong that the stars can also affect each other’s motions. These types of clusters are mainly found above or below the main galaxy. Like other stars, they revolve around the center of the galaxy, but because they are away from the main plane, their orbits appear to be tilted.

A very famous example of a globular constellation is Omega Centauri in the constellation Naraturanga (Centaurus). The largest, most massive, and most luminous of the approximately 150 globular clusters associated with our Milky Way Galaxy, this star cluster is easily visible to the naked eye through the dark region. Its total mass is 40 million times that of the Sun and its millions of stars are 12 billion years old.

Since the stars in a cluster are usually born from the same massive cloud (a supermassive cloud composed mainly of hydrogen) and at the same time, many conclusions can be drawn about the evolution of stars from how many stars in a cluster have reached which stages over time. 


Like the Milky Way, other galaxies also have numerous star clusters. By studying the stars in a constellation, solid predictions can be made about the origin and future of the entire galaxy. 


Also, the study of constellations is useful for measuring different distances in space, since the constituent stars of a constellation are nearly equally spaced. Like the Milky Way, in other galaxies, open clusters are located near the main plane, while globular clusters are located above and below the plane, so the shape, composition, etc. of the galaxy can be predicted from their location. The in-depth study of constellations is of great importance in astronomy. Vast amounts of data collected by state-of-the-art survey telescopes such as Gaia are freely available on the Internet and are used by many amateur astronomers to study star clusters. 

If you have a similar amateur astronomer hidden in you, then you can also start your study of astronomy by observing constellations.

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