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arXiv · 1101.2253

Are C60 molecules detectable in circumstellar shells of R Coronae Borealis stars?

D. A. Garcia-Hernandez·N. Kameswara Rao·D. L. Lambert
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Abstract

The hydrogen-poor, helium-rich and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a site for formation of C60 molecules. This suggestion is not supported by observations reported here showing that infrared transitions of C60 are not seen in a large sample of RCB stars observed with the Infrared Spectrograph on the Spitzer Space Telescope. The infrared C60 transitions are seen, however, in emission and blended with PAH-features in spectra of DY Cen and possibly also of V854 Cen, the two least hydrogen-deficient (hydrogen deficiency of only ~10-100) RCB stars. The speculation is offered that C60 (and the PAHs) in the moderately H-deficient circumstellar envelopes may be formed by the decomposition of hydrogenated amorphous carbon but fullerene formation is inefficient in the highly H-deficient environments of most RCBs.

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D. A. Garcia-Hernandez, N. Kameswara Rao, D. L. Lambert. 2011-01-12. Are C60 molecules detectable in circumstellar shells of R Coronae Borealis stars?. https://doi.org/10.1088/0004-637x%2F729%2F2%2F126

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