NASA Hubble Space Telescope recently shared a stunning video of a spiral galaxy known as Caldwell 45, or NGC 5248.
About Spiral Galaxy:
Spiral galaxies are twisted collections of stars and gas that often have beautiful shapes and are made up of hot, young stars.
In a spiral galaxy, the stars, gas, and dust are gathered in spiral arms that spread outward from the galaxy's center.
Most of the galaxies that scientists have discovered so far are spiral galaxies, as opposed to the other two main categories of galaxy shapes—elliptical and irregular.
Approximately 60% of all galaxies are thought to be spiral galaxies.
The Milky Way, the galaxy that includes Earth and our solar system, is an example of a spiral galaxy.
Structure:
Most spiral galaxies contain a central bulge surrounded by a flat, rotating disk of stars.
The bulge in the center is made up of older, dimmer stars and is thought to contain a supermassive black hole.
Approximately two-thirds of spiral galaxies also contain a bar structure through their center, as does the Milky Way.
The disk of stars orbiting the bulge separates into arms that circle the galaxy.
These spiral arms contain a wealth of gas and dust and younger stars that shine brightly before their quick demise.
The majority of spiral galaxies rotate in the sense that the arms trail the direction of the spin.
The visible portion of spiral galaxies contains only a small fraction of the total mass of the galaxy, and that spiral galaxies are surrounded by an extensive halo consisting mostly of dark matter.
Spiral galaxies are thought to evolve into elliptical galaxies as the spirals get older.
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