Astral Imaging at Dogwood Ridge Observatory

Latitude: 3748'51.0" N"
Scottsville, Virginia 24590

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Contained within the confines of our home Galaxy, The Milky Way, exists areas of vast interstellar gases called Nebulae. These are designated by categories of Planetary, Reflection, Dark, Emission and Supernova Remnant. Each category is described below.

Planetary This is the result of ordinary stars that have turned into Red Giant Stars and then later died. In their death throes they cast off their external gas layers in violent eruptions. This will be the eventual fate of our own Sun many millions of years from now. The name Planetary was coined by early astronomers as the view they were afforded by their small telescopes reminding them of the planet Saturn. With the advent of modern telescopes we of course see that these are some of the most beautiful objects in the Universe. They also contain the needed ingredients for new star formation. Call it interstellar recycling.
Reflection This is resulting from light from nearby bright stars reflecting off the scattering of dust particles. The nearby stars are not hot enough to cause ionization of the gas of the nebula but bright enough to illuminate the dust. Due to the fact wavelengths in the blue are scattered more readily than red these nebula tend to be of blue color.
Dark Similar to reflection nebula except these are clouds of dust so thick that they block the light from stars that are behind them. These are often observed with reflection and emission nebula.
Emission These are clouds of high temperature gases. The atoms of these clouds are energized by ultraviolet light emitted from nearby stars and emitting radiation as they transform into lower energy states similar to the same way as neon light does. They are most often red due to the predominant emission line of hydrogen which is red in color. Other colors are produced by other atoms however hydrogen is most abundant. These nebula are usually often hot beds for new star birth.
Supernova Remnant These are formed as a result of a massive star ending it's life in a massive explosion or implosion. For a brief few days the supernova emits as much energy as an entire galaxy. This process results in a large amount of the star being blown into space thus forming a supernova remnant nebula.
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  Last Modified :01/23/09 12:40 AM