Abstract
THE triatomic molecules CO2 and HCN have now been reported to be present in cool stars1,2, and H2O had already been detected in the sunspot spectrum3–7. Dissociation equilibrium calculations for three recent sunspot models8–10 show that the molecules CO2 and HCN are fairly abundant in sunspots. The results for the Zwaan model have already been published11; we further find that the abundances of CO2 and HCN are comparable for all three models. We have therefore calculated equivalent widths of selected lines of these molecules to ascertain if they might show up in the infrared region of the sunspot spectrum. The strongest fundamental bands of HCN and CO2 and a weaker band of CO2 were included in our calculations. The selected J values correspond closely to the expected maximum Local Thermodynamic Equilibrium (LTE) population under sunspot conditions.
Similar content being viewed by others
Article PDF
References
Carleton, N. P., Liller, W., and Roeslar, F. L., Astrophys. J., 154, 385–387 (1968).
Giguere, P. T., Astrophys. J., 186, 585–588 (1973).
Wöhl, H., Solar Phys., 9, 394–396 (1969).
Mallia, E. A., and Blackwell, D. E., Solar Phys., 12, 101–103 (1970).
Mallia, E. A., Blackwell, D. E., and Petford, A. D., Nature, 226, 735–737 (1970).
Mallia, E. A., Blackwell, D. E., and Petford, A. D., Solar Phys., 20, 369–371 (1971).
Steveland, L., Solar Phys., 26, 90–93 (1972).
Zwaan, C., Rech. astr. Obs. Utrecht, 17, part 4 (1965).
Henoux, J. C., Astr. Astrophys., 2, 288–308 (1969).
Stellmacher, G., and Wiehr, E., Astr. Astrophys., 7, 432–442 (1970).
Gaur, V. P., Pande, M. C., and Tripathi, B. M., Bull. astr. Inst. Czechoslovakia, 24, 138–143 (1973).
Gaur, V. P., Bull. astr. Inst. Czechoslovakia (in the press).
Penner, S. S., in Quantitative Molecular Spectroscopy and Gas Emissivities, ch. 6, 98 (Pergamon, London, 1959).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
PANDE, M., GAUR, V. CO2 and HCN in sunspots. Nature 253, 104 (1975). https://doi.org/10.1038/253104a0
Received:
Issue Date:
DOI: https://doi.org/10.1038/253104a0
This article is cited by
-
Rotovibrational states of the water molecule on the sun
Journal of Molecular Modeling (2016)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.