First Spitzer observations of Neptune: Detection of new hydrocarbons

We present the first spectra of Neptune taken with the Spitzer Space Telescope, highlighting the high-sensitivity, moderate-resolution 10–20 μm (500–1000 cm^(−1)) spectra. We report the discovery of methylacetylene (CH_3C_2H) and diacetylene (C_4H_2) with derived 0.1-mbar volume mixing ratios of (1.2±0.1)×10^(−10) and (3 ±1)×10^(−12) respectively.

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