Nebula Classification

Created by Captain Tim Williams on Sat May 25th, 2013 @ 9:20pm

Nebula Classification
A nebula is an interstellar cloud of dust, gas and plasma, where star formation usually occurs. In the year 2400, the Federation introduced a new system to classify nebulae. The new system first assigns the nebula a letter designation based upon its general composition. If the nebula has any unusual quirks, it is assigned an additional number designation. For example, a Class F2 Nebula is a Dark Nebula that contains disruptive electromagnetic radiation.

Nebula Class A · Emission Nebula
	COMPOSITION: Hydrogen, helium, oxygen AVERAGE SIZE: 100 - 5,000 ly AVERAGE TEMP.: 10° - 20° K LIFESPAN: 1 - 2 million years COLOUR: Red, green, blue EXAMPLE: Lagoon Nebula, Veil Nebula PICTURED: Krai`jih`na Nebula	Emission nebulas are large clouds of ionized plasma where star formation usually takes place. They are illuminated from within by groups of young stars that form in H II Regions within the nebula.

Nebula Class B · H II Region
COMPOSITION: Hydrogen, helium AVERAGE SIZE: 20 - 2,000 ly AVERAGE TEMP.: 10,000° K LIFESPAN: 1 - 2 million years COLOUR: Red, pink EXAMPLE: Eagle Nebula PICTURED: Cone Nebula	An H II Region is a large stellar nursery, typically located inside an emission nebula. Over the duration of its lifespan, an H II Region can give birth to thousands of stars. Gravimetric forces by the larger stars will eventually disperse the nebula and leave behind a star cluster similar to the Pleiades.

Nebula Class C · Bok Globule
	COMPOSITION: Hydrogen, helium, carbon AVERAGE SIZE: 1 ly AVERAGE TEMP.: 3° K LIFESPAN: 1 - 2 million years COLOUR: Black EXAMPLE: NGC 281, NGC 1999, BHR 71 PICTURED: IC 2499	While an H II Region can span light years and contain dozens of stars in varying states of development, Bok Globules are dense clusters of dust and gas where star formation actually takes place. They commonly result in binary and trinary star systems.

Nebula Class D - Reflection Nebula
COMPOSITION: Hydrogen, carbon, iron, nickel AVERAGE SIZE: 100 ly AVERAGE TEMP.: 25,000° K LIFESPAN: 10 million - 10 billion years COLOUR: Blue, purple EXAMPLE: Trifid Nebula, Witchhead Nebula PICTURED: Pleiades Cluster	Reflection nebulas are large clouds of dust that reflect light from nearby stars. The nearby stars are not usually hot enough to cause ionization, but are bright enough to make the dust visible. Star formation can occur within a reflection nebula.

Nebula Class E · Planetary Nebula
	COMPOSITION: Carbon, oxygen, nitrogen, calcium AVERAGE SIZE: 1 ly AVERAGE TEMP.: 10,000° K LIFESPAN: 10,000 years COLOUR: Orange, green, blue EXAMPLE: Ring Nebula, Hourglass Nebula PICTURED: Cat's Eye Nebula	Despite the name, planetary nebulas have nothing to do with planets. They are, in fact, the final stage of life for most stars, developing when a star is no longer able to sustain nuclear fusion. As the star's core contracts, it ejects ionized gases into space, creating a planetary nebula. This plays a crucial role in the evolution of the galaxy, for the process returns material to the interstellar medium.

Nebula Class F - Dark Nebula
COMPOSITION: Hydrogen AVERAGE SIZE: 200 ly AVERAGE TEMP.: 7° K LIFESPAN: 1 - 2 million years COLOUR: Black EXAMPLE: Coalsack Nebula, Snake Nebula PICTURED: Horsehead Nebula	Dark nebulas are a type of large molecular cloud. The cloud cores are completely invisible to the naked eye, and are undetectable aside from microwave emissions from the molecules within. Dark nebulas have strong magnetic fields that create considerable gravimetric forces in and around the nebula. Stars and astrophysical masers can form deep inside dark nebulas.

Nebula Class G · Supernova Remnant
	COMPOSITION: Ionized hydrogen, oxygen AVERAGE SIZE: 3 ly AVERAGE TEMP.: 10,000,000° K LIFESPAN: 1,000,000 years COLOUR: Varies; typically orange, blue EXAMPLE: Tycho's Remnant, 1987A PICTURED: Crab Nebula	When a massive star reaches the end of its life, it explodes in an immensely powerful supernova. This event blows the entire star apart, leaving in its wake a remnant nebula that expands into the interstellar medium.

Nebula Class H - Nova Remnant
COMPOSITION: Ionized hydrogen, oxygen AVERAGE SIZE: 0.5 ly AVERAGE TEMP.: 5,000° K LIFESPAN: 300 years COLOUR: Varies; typically blue, orange EXAMPLE: RR Pictoris PICTURED: T Pyxidis	Nova remnants are similar to supernova remnants, only much smaller on all levels. They are also much more common.

Nebula Class I · Solar Nebula
	COMPOSITION: Hydrogen, helium, oxygen AVERAGE SIZE: 100 AU AVERAGE TEMP.: 150° K LIFESPAN: 2,000,000 years COLOUR: Yellow, orange EXAMPLE: Panak PICTURED: A generic solar nebula	While most stars form within emission nebulas, there are exceptions to the rule. When a young star forms elsewhere, gravimetric forces gradually attract a disc of dust and gas that flatten to form a new star system that includes planets and asteroids.

Nebula Class J - Wolf-Rayet Nebula
COMPOSITION: Helium, carbon, oxygen AVERAGE SIZE: 0.5 ly AVERAGE TEMP.: 25,000° - 50,000° K LIFESPAN: 1 - 2 million years COLOUR: Blue EXAMPLE: NGC 6888, NGC 3199 PICTURED: Gamma Velorum	A Wolf-Rayet nebula forms when strong stellar winds cause a Class O star to rapidly lose its mass. The dispersed mass forms a nebulous halo around the star.

Nebula Class K · Inversion Nebula
	COMPOSITION: Ionized plasma strings AVERAGE SIZE: 200 AU AVERAGE TEMP.: 10,000° K LIFESPAN: 5 - 10 years COLOUR: Pink EXAMPLE: Lukkaris Nebula PICTURED: Marayna's Nebula	Inversion nebulas are rare, highly unstable nebulas created by plasma strings. They typically burn out after a few years.

Additional Subtype Classifications

Type 1 · Protomatter
A nebula that contains amounts of protomatter.

Type 2 · Disruptive
A nebula that contains disruptive electromagnetic radiation.

Type 9 · Shadow
An ultra-dense nebula with constituent compounds that create sensor shadows. Prolonged exposure is detrimental to humanoid nervous systems.

Type 10 · Deuterium
A nebula that contains deuterium.

Type 11 · Argon
A nebula that contains argon. Thetazenon, fluorine and sirillium can also be present.

Type 13 · Mutara
A nebula that contains high levels of static discharge and ionized gases; renders shields and sensors inoperable.

Type 16 · Protostellar
A nebula still in its formative stages. Has high levels of particle flux.

Type 17 · Sirillium
A nebula that contains amounts of sirillium.

Data and images from www.sttff.net

Categories: Stellar Cartography