A search for absorption in the fourth positive system of CO in the spectrum of the planetary nebula IC 418.
DOI: 10.1093/mnras/190.1.1P
Bibcode: 1980MNRAS.190P...1C
Clavel, J.; Flower, D. R.
Spain, United Kingdom
Abstract
The continuous emission of IC 418 has been observed at high dispersion with the IUE satellite and the spectrum searched for the A1Π-&Chi1Σ+ bands of CO. It was not possible to unequivocally detect these CO bands in IC 418. However, an upper limit to the absorption by CO was determined, giving a column density which is much less than the value implied by the J = 1 → 0 rotational transition at 2.6 mm.
1980
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Monthly Notices of the Royal Astronomical Society
IUE
2