Terence Galuszka Astrophotography
astronomypix.com
Nebulae
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The Keyhole Nebula |
The Horsehead Nebula |
Pillars of Creation |
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Types of Nebulae
There are 5 types of nebulae, so hang in there I'll try to make this brief!
Reflection Nebula -such as M45 'The Pleiades' where the dust and gas of this nebula does not
emit its own light; it merely reflects the light from the nearby star.
Emission Nebula - The Great Orion Nebula in the
constellation Orion. In this case the nebula surrounds a young star cluster
and is emitting its own light and due to the presence of ultraviolet
radiation from the hot young stars the atoms in the interstellar
dust and gas vibrate and emit their own radiation.
Dark Nebula - The Horsehead nebulae in Orion is a fantastic example
of a dark nebulae where the clouds of
gas and dust absorb and block some light from behind them. The
absorbed light heats up the dust particles and emits some of the energy as infrared light,
whilst some of the background light is
scattered into the surrounding area creating a contrast between the
background and foreground.
Planetary Nebula - Basically a star that expands to a super giant and
cases off its outer layers leaving behind a tiny white speck at the
centre, and a colourful ring around the outside. It's not a
supernova, but an ejection of matter at low speed. Very high
temperature radiation causes the ejected gases to become ionized and
glow; typically red and blue think dumbbell Nebula M27.
Supernova Remnants -The crab nebula in Taurus. When a
star goes supernova, as in 1054 when a star in Taurus exploded creating the Crab
nebula. In short this stars mass exceeded a certain value under went rapid Carbon burning and exploded immediately ejecting the
equivalent of 1 solar mass (The Sun's mass) of matter.
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