The organic volatile composition of the long-period comet C/1999 H1 (Lee) was investigated using the first of a new generation of cross-dispersed cryogenic infrared spectrometers (NIRSPEC, at the Keck Observatory atop Mauna Kea, HI). On 1999 August 19-21 the organics spectral region (2.9-3.7 μm) was completely sampled at both moderate and high dispersion, along with the CO fundamental region (near 4.67 μm), revealing emission from water, carbon monoxide, methanol, methane, ethane, acetylene, and hydrogen cyanide. Many new multiplets from OH in the 1-0 band were seen in prompt emission, and numerous new spectral lines were detected. Several spectral extracts are shown, and global production rates are presented for seven parent volatiles. Carbon monoxide is strongly depleted in comet Lee relative to comets Hyakutake and Hale-Bopp, demonstrating that chemical diversity occurred in the giantplanets' nebular region.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science