The Concentration of Calcium Ions and of Free Electrons in a Meteor Coma

Prism spectra are studied of eight bright meteors, belonging to different showers and photographed by small cameras in the Gissar observatory of the Institute of Astrophysics, Tajik Academy of Sciences. Monochromatic light curves for the H and K spectral lines of the ionized calcium doublet are constructed and from the ratio of their intensities at selected points along the meteor trajectories the column N-Call and the volume n(Call) concentrations of calcium ions are determined. The obtained values N-Call = 10(16)-10(18) cm(-2) and n(Call) = 10(13)-10(15) cm(-3) are in good agreement with the estimates of calcium abundance obtained by other methods and confirm that there is almost full ionization of calcium atoms in meteor comae. The volume concentration of free electrons n(e) = 4 x 10(13) cm(-3) is defined, and the excitation temperature is calculated along the meteor paths.