How Many Galaxies in the Universe?


You will be surprised after knowing the number of galaxies in the universe. When you look up at the night sky through the veil of stars and the Milky Way plane close by, you cannot help but feel small in comparison to the vastness of the universe that lies beyond. Our observable universe stretches out in all directions for tens of billions of light years. And nearly all of them are invisible to our naked eyes.
The precise number of galaxies out there has remained a mystery, with estimates ranging from thousands to millions to billions as telescope technology advanced. Two trillion galaxies are the most recent estimate. A handful of galaxies without dark matter have recently been discovered. This could lead to the creation of entirely new types of galaxies, but for the time being, it raises more questions than it answers.

Milky Way    

Our galaxy, the Milky Way, is just one of many galaxies in the universe, and it is not even a large one. Its diameter is approximately 105,700 light years. Milky Way is considered to be home of a minimum of 400 billion stars and 100 billion planets. We would have to abandon our calculators if we tried to calculate how many planets and stars those two trillion galaxies would contain. This is especially true given that some galaxies are hundreds of times the size of our Milky Way galaxy.

Who is Edwin Hubble?

Edwin Hubble is an American astronomer who is widely recognized as the premier observational cosmologist of the twentieth century. He is a crucial figure in the development of extragalactic astronomy. In the 1920s, Hubble and others found that the universe was expanding by observing that most galaxies were receding from the Milky Way and that the farther they were from the Milky Way, the quicker they were receding.

How Many Galaxies Are There In the Universe?

In our Milky Way, there exists satellite galaxies, which are very small galaxies gravitationally coupled to larger ones. These tiny galaxies have been or are being eaten by their larger counterparts. The Large and Small Magellanic Clouds, for example, are satellite galaxies of the Milky Way. In the Milky Way, there are about fifty galaxies, with the Large Magellanic Cloud being the largest. Only 14,000 light years separate this satellite galaxy from the central galaxy. There could be up to 10 billion stars in the Large Magellanic Cloud. This small galaxy will collide with our Milky Way in roughly 2.4 billion years.  Each galaxy is distinct, ranging in size from tens of thousands to hundreds of thousands of light years. Spiral, barred spiral, lenticular, elliptical, and irregular galaxies are the five types of galaxies. Our galaxy, the Milky Way, is considered to be a barred spiral galaxy.

Classification of galaxies

Edwin Hubble initially divided spiral galaxies into types: barred spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies were discovered to be the most frequent type of galaxy in the universe.
•    Barred Spiral Galaxies: A barred spiral galaxy is one that has a core bar-shaped structure made up of stars. About half of all spiral galaxies contain bars. Within spiral galaxies, bars often affect both star and interstellar gas motions, as well as spiral arms.
•    Elliptical Galaxies: Elliptical galaxies are the most common type of galaxy in the universe, although they're often overshadowed by younger, brighter clusters of stars due to their age and dull features.
•    Irregular Galaxies: The most uncommon of galaxies are irregular galaxies. These neither falls in the spiral nor elliptical galaxy families. They don't have beautiful spiral arms, but they do have dark gas and dust patches. Some irregular galaxies seem to be an outcome of collision of two galaxies.

A ring of stars and interstellar medium surrounds the bare core in some galaxies. Smaller galaxies are thought to pass through the roots of spiral galaxies, giving them this form. Lenticular galaxies resemble spiral and elliptical galaxies. With an oval halo of stars, they have ill-defined spiral arms.  Some galaxies are classed as ultra-diffuse galaxies because their densities are exceedingly low. Despite being as large as our Milky Way, only about 1% of the visible stars are visible. This is due to a shortage of star-forming gas. On the other hand, starburst galaxies are characterized by dusty gas concentrations and the appearance of newly born stars. Many of these stars are often big, resulting in supernova explosions that interact strongly with the surrounding gas.

Largest Galaxy

A ring of stars and interstellar medium surrounds the bare core in some galaxies. Smaller galaxies are thought to pass through the roots of spiral galaxies, giving them this form. Lenticular galaxies resemble spiral and elliptical galaxies. With an oval halo of stars, they have ill-defined spiral arms.
The supergiant elliptical galaxy IC 1101 is the largest galaxy in the universe yet discovered. This galaxy is roughly 5.5 million light years large and includes well over 100 trillion stars. IC 1101 is almost 50 times the size of our Milky Way Galaxy. It is located one billion light years (320 megaparsecs) away from us.

Conclusion

Despite the overall expansion of the universe, which means most galaxies are moving away from one another as the universe expands, gravity maintains a smaller number of galaxies tied together on their trips. There are many galaxies in the universe. On the one hand, it is true that the cosmos is so vast that it is difficult to understand. Our brief lives pass us by so rapidly that we are generally ignorant of the vast cosmos that surrounds us. However, the fact that we are sentient beings who can contemplate distant stars and galaxies makes life in the universe a genuinely marvellous thing. And we are only scratching the surface of the vast universe of galaxies.

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