Spectral Classification
Created by Captain Tim Williams on Sat May 25th, 2013 @ 9:33pm
Spectral Classification |
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Spectral classification is the classification of stars based upon the temperature of the
photosphere. Each spectral class is further divided into 10 subclasses, ranging from 0
(hottest) to 9 (coolest). Stars are also placed into one of six categories based upon
luminosity: 1a (luminous supergiants), 1b (less luminous supergiants), II (luminous giants), III
(normal giants), IV (subgiants), and V (main sequence and dwarf stars). For example, Sol is classified as type G2V. This indicates that is a Spectral Class G star of considerable temperature, and that it is a part of the main sequence. |
Spectral Class O |
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COLOUR: Dark blue/violet SURFACE TEMP: 28,000° - 50,000° K COMPOSITION: Ionized atoms, helium MASS: 60 Sols RADIUS: 15 Sols LUMINOSITY: 1,400,000 MAGNITUDE: -3 ABUNDANCE: 0.0000002135% of all stars LIFETIME: 10 million years EXAMPLES: Mintaka, Kalidar |
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Spectral Class B |
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COLOUR: Blue SURFACE TEMP: 10,000° - 28,000° K COMPOSITION: Neutral helium, some hydrogen MASS: 18 Sols RADIUS: 7 Sols LUMINOSITY: 20,000 MAGNITUDE: -6 ABUNDANCE: 0.13% of stars LIFETIME: 100 million years EXAMPLES: Rigel, Alpha Eridani |
Spectral Class A |
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COLOUR: Light blue SURFACE TEMP: 7,500° - 10,000° K COMPOSITION: Strong hydrogen and ionized metals MASS: 3.2 Sols RADIUS: 2.5 Sols LUMINOSITY: 80.0 MAGNITUDE: +1 ABUNDANCE: 0.63% of stars LIFETIME: 1 billion years EXAMPLES: Vega, Sirius |
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Spectral Class F |
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COLOUR: White SURFACE TEMP: 6,000° - 7,500° K COMPOSITION: Hydrogen and ionized metals, calcium and iron MASS: 1.7 Sols RADIUS: 1.3 Sols LUMINOSITY: 6.0 MAGNITUDE: +3 ABUNDANCE: 3.1% of stars LIFETIME: 3 billion years EXAMPLES: Canopus, Procyon |
Spectral Class G |
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COLOUR: Yellow SURFACE TEMP: 5,000° - 6,000° K COMPOSITION: Ionized calcium, neutral and ionized metals MASS: 1.1 Sols RADIUS: 1.1 Sols LUMINOSITY: 1.2 MAGNITUDE: +5 ABUNDANCE: 8% of stars LIFETIME: 10 billion years EXAMPLES: Sol, Ka`Tula, Capella |
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Spectral Class K |
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COLOUR: Orange SURFACE TEMP: 3,500° - 5,000° K COMPOSITION: Neutral metals MASS: 0.8 Sols RADIUS: 0.7 Sols LUMINOSITY: 0.4 MAGNITUDE: +10 ABUNDANCE: 13% of stars LIFETIME: 50 billion years EXAMPLES: Arcturus, Aldebaran, Alpha Centauri |
Spectral Class M |
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COLOUR: Red SURFACE TEMP: 2,500° - 3,500° K COMPOSITION: Ionized atoms, helium MASS: 0.2 Sols RADIUS: 0.3 Sols LUMINOSITY: 0.04 MAGNITUDE: +15 ABUNDANCE: 78% of stars LIFETIME: 200 billion years EXAMPLES: Betelgeuse, Proxima Centauri, Wolf 359 |
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Categories: Stellar Cartography