Stellar classification (astrophysics): Difference between revisions
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Stars are classed by various properties. A common classification is surface temperature. Beginning with early spectral schema in the 19th century ranking stars from A to P, the spectral classification, called “Morgan-Keenan spectral classification” <ref>Note: based on the work of Annie Cannon and other astronomers from the Harvard College Observatory</ref><ref>[http://www.sdsc.edu/ScienceWomen/cannon.html Annie Jump Cannon] 1983-1941</ref> now ranks stars in seven main types: | Stars are classed by various properties. A common classification is surface temperature. Beginning with early spectral schema in the 19th century ranking stars from A to P, the spectral classification, called “Morgan-Keenan spectral classification” <ref>Note: based on the work of Annie Cannon and other astronomers from the Harvard College Observatory</ref><ref>[http://www.sdsc.edu/ScienceWomen/cannon.html Annie Jump Cannon] 1983-1941</ref> now ranks stars in seven main types: O, B, A, F, G, K, M.<ref>A popular mnemonic for this is '''O'''h '''B'''e '''A''' '''F'''ine '''G'''irl, '''K'''iss '''M'''e</ref> Each spectral classification is further divided into tenths. Our sun, Sol is a G2. | ||
==Classification system== | ==Classification system== | ||
Revision as of 20:44, 23 October 2007
Stars are classed by various properties. A common classification is surface temperature. Beginning with early spectral schema in the 19th century ranking stars from A to P, the spectral classification, called “Morgan-Keenan spectral classification” [1][2] now ranks stars in seven main types: O, B, A, F, G, K, M.[3] Each spectral classification is further divided into tenths. Our sun, Sol is a G2.
Classification system
The stars are ranked from hottest to coldest:
Class Temperature Star colour
- O 30,000-60,000 °K Blue
- B 10,000-30,000 °K Blue
- A 7,500-10,000 °K White
- F 6,000-7,500 °K White (yellowish)
- G 5,000-6,000 °K Yellow (e.g. Earth’s sun)
- K 3,500-5,000 °K Orange
- M 2,000-3,5000 °K Red
References
- ↑ Note: based on the work of Annie Cannon and other astronomers from the Harvard College Observatory
- ↑ Annie Jump Cannon 1983-1941
- ↑ A popular mnemonic for this is Oh Be A Fine Girl, Kiss Me
- ↑ Star classification