Carbon Star Spectra
By definition carbon stars have dominant spectral Swan bands from the molecule C2. Many other carbon compounds may be present at high levels, such as CH, CN (cyanogen), C3 and SiC2. Carbon is formed in the core and circulated into its upper layers, dramatically changing the layers' composition. Other elements formed through helium fusion and the s-process are also "dredged up" in this way, including lithium and barium.
When astronomers developed the spectral classification of the carbon stars, they had considerable difficulty when trying to correlate the spectra to the stars' effective temperatures. The trouble was with all the atmospheric carbon hiding the absorption lines normally used as temperature indicators for the stars.
Carbon stars also show a rich spectrum of molecular lines at millimeter wavelengths and submillimeter wavelengths. In the carbon star IRC+10216 more than 50 circumstellar molecules have been detected. This star is often used to search for new circumstellar molecules.
Read more about this topic: Carbon Star
Famous quotes containing the word star:
“Don Pedro. To be merry best becomes you; for, out o’ question, you were born in a merry hour.
Beatrice. No, sure, my lord, my mother cried; but then there was a star danced, and under than was I born.”
—William Shakespeare (1564–1616)