Search for Organic Matter in Leonid Meteoroids

Near-ultraviolet 300-410 nm spectra of Leonid meteors were obtained in an effort to measure the strong B to X emission band of the radical CN in Leonid meteor spectra at 387 nm. CN is an expected product of ablation of nitrogen containing organic carbon in the meteoroids as well as a possible product of the aerothermochemistry induced by the kinetic energy of the meteor. A slitless spectrograph with objective grating was deployed on FISTA during the 1999 Leonid Multi-Instrument Aircraft Campaign. Fifteen first-order UV spectra were captured near the 02:00 UT meteor storm peak on November 18. It is found that neutral iron lines dominate the spectrum, with no clear sign of the CN band. The meteor plasma contains less than one CN molecule per three Fe atoms at the observed altitude of about 100 km.