Resolved CN Band Profile of Stardust Capsule Radiation at Peak Heating

During the 2006 Stardust Sample Return Capsule entry observing campaign, the highest spectral resolution data gathered onboard NASA's DC-8 Airborne Laboratory was measured with a fixed-mounted slitless cooled charge. coupled-device spectrograph, called ASTRO. Spectra were recorded around the time of peak heating similar to 09 : 57 : 33 Coordinated Universal Time (UTC) on 15 January. The data covered three 0.8-second time intervals centered on 09:57:32.5, 34.4 and 36.3 s (+/- 0.5 s) UTC, when the capsule was at an altitude of 60 and 210 km from the spectrometer. The observed spectrum was a composite of first-, second-, and third-order emissions. The first-order spectrum contained only continuum emission. Second-order emissions included the 615 nm atomic line of oxygen: third-order emissions included the CN violet 0-0 band, the isoelectric N(2)(+) band, and two Ca(+) atomic lines. The Ca(+) lines had an instrumental full-width at half-maximum of 0.15 +/- 0.01 nm. The CN violet band contour measured vibrational and rotational excitation temperatures of T(v) = T(r) = 8, 000 +/- 1, 000 K, if self-absorption is neglected.