Millimeter-wavelength spectra were obtained of the parent molecules CO, CH_3OH, HCN, and H_2CO (ortho- and para-) in comet Hyakutake (C/1996 B2) with the NRAO 12-m telescope from 1996 Mar - May. The molecules were measured during pre-perihelion to have abundances relative to water of 0.30, 0.008, 0.003, and 0.002, for CO, CH_3OH, HCN and H_2CO, respectively. The measured Q(HCN) is similar to that found for CN by Millis & Schleicher (IAU 6344), which suggests a direct link between the two species. However, the CO and H_2CO data indicate that formaldehyde is not the main parent of the observed CO. The relative abundances of CO, CH_3OH, HCN and H_2CO will be compared before, during and after perihelion to search for chemical variations over the comet's passage. Each species was mapped over several arcminutes on the sky and modeling of these data will be also presented.
American Astronomical Society Meeting Abstracts #188
- Pub Date:
- May 1996