Time resolved spectroscopy of a Leonid fireball afterglow

Citation
J. Borovicka et P. Jenniskens, Time resolved spectroscopy of a Leonid fireball afterglow, EARTH MOON, 82-3, 2000, pp. 399-428
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
EARTH MOON AND PLANETS
ISSN journal
0167-9295 → ACNP
Volume
82-3
Year of publication
2000
Pages
399 - 428
Database
ISI
SICI code
0167-9295(2000)82-3:<399:TRSOAL>2.0.ZU;2-K
Abstract
Two video spectra of a meteoric afterglow were obtained for the first time during the 1999 Leonid aircraft campaign. The train was produced by a -13 m agnitude Leonid fireball at a relatively low height between 91-75 km. The m eteor spectrum has a strong hydrogen emission, proportional to 10-20 II ato ms per one Fe atom The train spectrum consisted of a red continuum, yellow continuum, and about 50 atomic lines between 3700-9000 Angstrom. The yellow continuum, possibly due to NO2, was also detected in the persistent train. The red continuum is interpreted as a thermal radiation of dust from meteo ric debris at about 1400 K. Evidence for secondary ablation is found in the afterglow. The atomic lines decayed within seconds of the meteor. The line s of Fe I, Mg I, Na I, Ca I, Ca II, Cr I, Mn I, K I, and possibly Al I were present in the glow together with the 5577 Angstrom forbidden O I line. Th e gas temperature in the train was close to 5000 K at the beginning and dec ayed to 1200 K within two seconds. However, thermal equilibrium was not sat isfied for all populated levels.