The Nebula: A Galactic Nursery with Supernova Remnants
Nebulae are enormous clouds of interstellar dust and gas (usually hydrogen and helium). In the vastness of space, over long periods of time, dust and gas are often drawn together by their own weight and gravitational attraction. The gravitational attraction continues as more matter is drawn into the cloud and sometimes the mass gets so great that the cloud will collapse to form stars. The intense heat and radiation from these infant stars cause the remaining dust and gas to ionize and glow so that they can be seen. Probably the most famous example of this type of nebula has been called the “the Pillars of Creation” which can be found within the Eagle Nebula.
Another famous nebula is the Horsehead Nebula which is in the constellation Orion (quite possibly my favorite constellation, by the way)! The Horsehead Nebula can be located just below the star Alnitak in Orion’s belt.
There are many different types of Nebulae including Diffuse Nebulae – which have no clearly defined boundaries, Planetary Nebulae – which are gas shells ejected by white dwarf stars, and Supernova Remnants – which are created by the most violent act in the universe – the explosion of a star. Isn’t it ironic that the most beautiful thing in the universe can be created by the most violent event?