Phenomena Associated with the Flight of Ultra-Speed Pellets. Part II. Spectral Character of Luminosity

Abstract

The spectroscopic character of the luminous trails generated by ultra-speed pellets has been investigated. A total of seven spectrograms have been measured and reduced. Three of these were of 5.0 km/sec aluminum pellets; two were of 5.9 km/sec magnesium pellets; one was of a 6.0 km/sec magnesium-lithium-aluminum pellet; and one was of a titanium pellet whose velocity was estimated at about 4.5 km/sec. The pronounced features of the spectrograms are: (1) AlO bands in the aluminum spectra, (2) Mg lines and MgO bands at the magnesium spectra, (3) strong Li lines and a pronounced continuum in the magnesium-lithium-aluminum spectra, and (4) TiO bands in the titanium spectra. Other features of the spectra are: (1) prominent AlI lines at λλ3944 and 3961 and a relatively weak continuum in the aluminum spectra, (2) a stronger continuum in the magnesium spectra, and (3) relatively weak MgO bands in the Mg-Li spectra. The time resolved spectra show that the AlO persists in the excited state twice as long as the aluminum. The aluminum oxidizes almost completely leaving AlO in an excited state which continues to emit light after the aluminum is burned.