Nebulae are known for their attractive colors and breathtaking views all over space. For many years, they have raised several questions for astronomers who were bewildered by their colors and wondered how and what they are formed from.
What is a Nabula?
Nebulae consist of huge masses of gases and dust. Some have formed due to supernova explosions, while some represent the starting point of star formation, and are known as "stellar nurseries".
Nebulae are mainly made of hydrogen and helium, which spread widely and swiftly in space. However, as gravity slows down their speed, they start to form huge masses of gases and dust; the more these masses grow, the stronger their gravity becomes.
Nebulae spread across outer space, mainly in interstellar areas. They have irregular shapes and are famous for their stunning colors and forms.
Types of Nebulae
Dark Nebula: A huge cloud of cold gases and dust that does not emit any light. In that sense, a dark nebula hides the stars it contains inside.
Reflection Nebula: It consists mainly of hydrogen, with some dust. It reflects light to the stars it encompasses. Dust contributes to giving these nebulae their blue color. The Pleiades Cluster is a vivid example of a Blue Nebula.
Diffusion Nebula: This type of nebula acquires its name because it emits its own light. Hydrogen atoms representing their main constituents are affected by the powerful ultraviolet rays omitted from nearby stars, causing them to ionize. In other words, the hydrogen atom loses its only electron and releases a photon that causes light emission.
Planetary Nebula: When a diffusion nebula is linked to the birth of a new star, the planetary nebula represents the residues of this star. The planetary nebula acquires its name due to its roundish sides.
Famous Space Nebulae
Helix Nebula: The NGC 7293 nebula is the closest nebula to Earth, at a distance of 700 light years. It was discovered by Karl Ludwig Harding in 1824, and it might have formed as a result of a star explosion.
The Cat's Eye Nebula is a planetary nebula that is about 3262 light years from Earth; it is located in the Draco Constellation. It was discovered by William Herschel in 1786, and is the most luminous nebula in space. It was also one of the first nebulae to be studied; it was studied by William Higgins in 1864.
The Butterfly Nebula: It is 4000 light years from Earth and is located in the Scorpius Constellation. It was discovered by astronomer Rudolph Minkowski in 1947. The Butterfly Nebula is characterized by the two wings shape that was formed due to the death of a star that is five times larger than the Sun. It is surrounded by huge dust clouds that emit ultraviolet rays.
The Crab Nebula: It is 6523 light years from Earth and is located in the Taurus Constellation. The Crab Nebula is the first astronomical object to be discovered as a by-product of a supernova explosion. The nebula is full of several mysterious threads that are extremely light and swift.
The Eagle Nebula is one of the most beautiful nebulae in space; it acquired its name because its shape resembles that of the bird. The nebula is 7000 light years from Earth and is located in the Serpens Constellation. This diffusion nebula comprises some active stars that stimulate the formation of gases and dust.
References
spaceplace.nasa.gov
astronoo.com
astronomyisawesome.com
Cover image Credits: NASA, ESA, J. Hester and A. Loll (Arizona State University).