2.1 Spectral Classifications

Created by on 21 Feb 2016 @ 1:56pm

Spectral Classification

Stars can generally be classified by their color. A purple star is always Class O, a yellow star is always Class G. However, there can be vast differences within each class. Most Class M stars are tiny and don't emit much light... however, many K- and G-type stars can evolve into red giants. That makes them Class M, but they are NOTHING like the tiny stars that make up the vast majority of Class M stars. Since most stars spend most of their lives on the Main Sequence, the descriptions on this page can be applied to the majority of stars. The oddballs and outsiders don't necessarily fit the exact parameters here (and will be discussed elsewhere), but even the oddballs conform to the interstellar color scheme, so even a blue oddball is class B.




Spectral Class O


Color: Dark blue/violet
Surface Temp: 28,000° - 50,000° K
Composition: Ionized atoms, helium
Mass: 60 sols
Radius: 15 sols
Lumosity: 1,400,000
Magnitude: -3
Abundance: 0.00000003125% of all stars
Lifetime: 10 million years
Death: Supernova, becomes a black hole or neutron star.
Examples: Mintaka, Kalidar, Zeta Puppis

Spectral Class B


Color: Blue
Surface Temp: 10,000° - 28,000° K
Composition: Neutral helium, some hydrogen
Mass: 18 sols
Radius: 7 sols
Lumosity: 20,000
Magnitude: -6
Abundance: 0.13% of all stars
Lifetime: 100 million years
Death: Supernova, becomes a neutron star>
Examples: Rigel, Alpha Eridani

Spectral Class A


Color: Light blue
Surface Temp: 10,000° - 28,000° K
Composition: Strong hydrogen and ionized metals
Mass: 3.2 sols
Radius: 2.5 sols
Lumosity: 80
Magnitude: +1
Abundance: 0.6% of all stars
Lifetime: 1 billion years
Death: becomes white dwarf
Examples: Vega, Sirius

Spectral Class F


Color: White
Surface Temp: 6,000° - 7,500° K
Composition: Hydrogen, ionized metals, calcium, iron
Mass: 1.7 sols
Radius: 1.3 sols
Lumosity: 6.0
Magnitude: +3
Abundance: 3% of all stars
Lifetime: 3 billion years
Death: Expands to a red giant, becomes planetary nebula and later, a white dwarf.
Examples: Canopus, Procyon

Spectral Class G


Color: Yellow
Surface Temp: 5,000° - 6,000° K
Composition: Ionized calcium, neutral and ionized metals
Mass: 1.1 sols
Radius: 1.1 sols
Lumosity: 1.2
Magnitude: +5
Abundance: 7.6% of all stars
Lifetime: 10 billion years
Death: expands to a red giant, becomes planetary nebula and later, a white dwarf.
Examples: Sol, Capella, Ka'Tula

Spectral Class K


Color: Orange
Surface Temp: 3,500° - 5,000° K
Composition: Neutral metals
Mass: 0.8 sols
Radius: 0.7 sols
Lumosity: 0.4
Magnitude: +10
Abundance: 12.1% of all stars
Lifetime: 50 billion years
Death: Expands to a red giant, becomes a white dwarf.
Examples: Arcturus, Aldebaran, Alpha Centauri

Spectral Class M


Color: Red
Surface Temp: 2,500° - 3,500° K
Composition: Ionized atoms, helium
Mass: 0.2 sols
Radius: 0.3 sols
Lumosity: 0.04
Magnitude: +15
Abundance: 76.45% of all stars
Lifetime: 1 trillion years or more becomes a white dwarf.
Examples: Proxima Centauri, Wolf 359

Spectral Class L


Color: Dark red
Surface Temp: 1,300° - 2,500° K
Composition: Metal hydride, neutral metals
Mass: 0.1 sols
Radius: 0.2 sols
Lumosity: 0.02
Magnitude: +20 (possibly very abundant)
Abundance: 1 trillion years or more
Examples: Becomes a brown dwarf

Spectral Class T


Color: Brown
Surface Temp: less than 1,300° K
Composition: Methane
Mass: 0.08 sols
Radius: 0.08 sols
Lumosity: 0.001
Magnitude: +25 (possibly very abundant)
Abundance: 1 trillion years or more

NOTICE: Classes L and T were created in 2006. You'd think that after 10 years, there'd be a bit more data about them, but most every source is woefully vague. I've done the best I can to put together profiles, but a lot of this is conjecture on my part. So like... don't take this stuff as fact.





This information comes from the website of Star Trek the Final Frontier.


Categories: Information Databank