===== On the Detection of Ethene toward CW Leonis =====
A. L. Betz\\
reported on\\
**[[https://doi.org/10.1086/183490|Ethylene in IRC +10216]]**\\
//Astrophys. J.// **244**, L103–L105 (1981).\\
Ethene, aka ethylene, was identified through two transitions (110 – 000 and 515 – 505) of the //v//7 out-of-plane infrared band near 949 cm−1 observed in absorption with the 1.5 m McMath Solar Telescope of the Kitt Peak National Observatory toward the C-rich AGB star CW Leonis. A rotational temperature greater than 400 K was inferred.\\
\\
J. P. Fonfría, K. H. Hinkle, J. Cernicharo, M. J. Richter, M. Agúndez, and L. Wallace\\
investigated\\
**[[https://doi.org/10.3847/1538-4357/835/2/196|The Abundance of C2H4 in the Circumstellar Envelope of IRC+10216]]**\\
//Astrophys. J. Lett.// **980**, Art. No. L13 (2025).\\
The Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF) was employed to observe 80 transitions of the //v//7 band with //J// up to about 30 toward CW Leonis. About 1/3 of the lines are unblended with rotational temperatures of about 105 and 400 K and the fractional abundance with respect to H2 around 10−8.\\
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Contributor(s): H. S. P. Müller; 10, 2025
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