A nebula is basically a cloud that is made up of gas and dust and is located in space . Some nebulae are regions where new stars are constantly forming , while others are remnants of stars or are dying. Nebulae come in many different shapes and sizes.
It is one of the most beautiful formations that can be seen in the space and are dust clouds interstellar which consists mostly of helium , hydrogen and other ionized gases , and is the place where are the stars.
The word nebula is a general term used to describe the different types of gas and dust clouds that exist in interstellar space . In other words, we can say that nebulae are concentrations of gas in which we find hydrogen , helium and stellar dust in greater quantities . Are structures that actually are very important for our universe, because inside it is the place where born the stars , which arise due to condensation and aggregation of matter.
Some nebulae are essentially places where new stars are brought to life , but there are also other types of nebulae in which what we can find are the remains of a series of dead or dying stars .
The main characteristics of the nebula are as follows:
- Nebulae are clouds of gas and dust in interstellar space.
- Its size can vary from millions of miles to hundreds of light years.
- They are composed mainly of hydrogen and also have other gases and dust particles .
- The stars and planetary systems are formed from the gas and dust is within nebulae.
- Until 1920 distant galaxies were classified as nebulae.
- Some can be seen in the night sky with the naked eye.
- The word nebula is derived from the Latin word for cloud , its plural is hazy, but also used nebulae .
Types of nebula
There are four main types of nebulae:
- Reflection nebulae : they reflect light from nearby stars that do not emit enough radiation so that these dust clouds reflect light from a nearby star . Example: the Pleiades nebula or seven sisters.
- Emission nebulae: they emit their own light because the ultraviolet light from the stars increases the hydrogen atoms , which is ionized, producing brightness. Example: the Omega nebula.
- Absorption nebulae : called dark nebulae , they do not emit light and hide the stars they contain. William Herschel , discovered this type of nebula. Example: the Horsehead nebula.
- Planetary nebulae : the light that comes from the associated star is absorbed by the atoms of the nebula. It has a series of outer layers shaped like a ring or a bubble . Example: the Helix Nebula.
Nebulae are formed when a star shows its layers more external when no longer has fuel to burn. These outermost layers that are made of gas expand into space, and in this way a nebula is created which is usually in the shape of a ring or bubble . They are then formed in the last stage of life that a star has and the layers of gas that it expels during this process are visible for a few hundred years.
Thanks to the scientists and technicians who operate the telescope Space Telescope and many other instruments incredibly complex and sensitive, we are privileged to see nebulae in all its majesty. Some of them can be seen from the ground .
How it differs from a galaxy
The difference between the two is that the nebula is a cloud in space made of gases and dust while galaxies are a set, which is composed of planets , stars, dust, nebulae and other interstellar elements that are joined by means of the gravity.
- The Orion Nebula is part of the Orion Molecular Cloud Complex interstellar cloud . It is located about 1,500 light years distant and contains hundreds of newborn stars and brown dwarfs . It is below the three stars of the Orion belt , and has a group of young stars called the Trapezium at its heart which are approximately two million years old and relatively young.
- The Horsehead Nebula is part of the Orion Cloud Complex , and is a dark nebula illuminated from behind by radiation from several nearby young stars. Astronomers have confirmed that stars are forming within the nebula and as they grow they will eat away at its birth cloud .
- The Eagle Nebula , known as M16 , is known as the “Pillars of Creation . ” It is the site of star birth regions hidden within gigantic pillars of gas and dust . Newborn stars devour the clouds, forming the shapes of the pillars.
- The Crab Nebula (M1) is a supernova remnant . It was formed when a star exploded in what is called a “core collapse” supernova . Most of its mass was launched to the space and the rest collapsed becoming a star of neutrons . It is called the ” pulsar in the crab nebula .”