Unexpected Finding Of Stellar Molecules

Carbon-rich stars were previously considered the most likely source for the galaxy's complex chemical makeup, but Lucy M. Ziurys and colleagues at the University of Arizona have now observed that oxygen-rich stars may be just as chemically prolific. The researchers report seven unexpected compounds in the oxygen-rich shell of VY Canis Majoris, which brings the total known compounds present in the red supergiant to 17—more than the 10–12 compounds of other oxygen-rich stars and on par with the diversity of compounds in carbon-rich stars (Nature 2007, 447, 1094). The researchers used microwave emission spectrometry to determine that the new compounds contain sulfur, phosphorus, silicon, or sodium and include the simple molecules HCN and NaCl. "The detection of additional gas-phase molecules will help us draw a more complete picture of chemical synthesis in stars," writes Sun Kwok of the University of Hong Kong in a related Nature commentary.