You may have seen a picture of a nebula before without actually knowing the term. So, what exactly is a nebula?
A nebula is a huge cloud of combined gas and dust in space. It can contain hydrogen, helium, and/or plasma. They are sometimes considered nurseries, because oftentimes they are the location where stars are created and born.
Nebulae, which is the plural form (more than one) of nebula, form when gas, like hydrogen and helium, as well as molecules, particles, ions, and electrons are pulled together by gravity. Some of the gas and dust particles group together to create common regions that have similar densities. In areas that become more dense, stars can form out of the collapsing material.
There are a few different kinds of nebula formations. Many nebulae have no clear beginning or end, and no clear boundaries. These are diffuse nebulae. Other kinds of nebulae are formed out of explosions of dying stars, and these are called supernova remnant nebulae. Another kind of nebula, a planetary nebula, is created with material lost from a red giant phase of a dying star. Reflection Nebulae cannot give off light by itself, but sources within its cloud can light it up. On the other hand, emission nebulae can give off their own light because they have ionized gas. These nebulae are extremely hot and have high-energy stars that give off UV photons.
When you look at a picture of a nebula, you will notice a variety of vibrant colors. You will often see hues of blue, purple, red, and white. These colors are actually occur due to the new stars that are forming. The newly-born stars release energy and radiation. The moving particles move and push the gas and dust surrounding it in the nebula. The cloud and gas moving cause the nebula to shift and change its shape overall. The energy released from the new stars lights up the nebula, creating the vibrant color and light.
The Orion Nebula is one of the most famous nebula, which happens to be about 1500 light-years away from us. You can find this nebula by finding the Orion constellation. Astronomers note that many stars are being born out of this nebula, especially in the location noted by Orion’s sword. This nebula has many colors. Astronomers know that the orange color is hydrogen, the red color in the nebula is sulfur, and the green color is oxygen.
When you think about a nebula, you can think of it it two ways: a nebula is a giant cloud of dust and gas in space, and a nebula is the place where stars are formed and born.