A statistical analysis of over three thousand meteors and their spectra

Abstract

ABSTRACT In this article, over three thousand meteor spectra recorded in Saitama, Japan, between 2018 and 2021 are analysed. We performed a principal component analysis of the intensity of the sodium and magnesium lines and the iron band of each meteor in combination with the orbital elements and the kinematic parameters such as the geocentric velocity and the initial and final altitudes to determine the relative importance of each of these variables in the composition of a meteor’s spectrum. We found that for meteor showers such as GEM, LEO, QUA, and PER, the orbital elements or kinematic parameters are important parameters that determine the intensity of these spectral lines, which could indicate the influence of gravitational and/or non-gravitational forces in distinguishing the composition or variations in the strength of the meteoroid material in each meteor shower. The normal spectral type in our sample ranges from 39.5 per cent to 96.8 per cent, corresponding to GEM and PER, respectively. The COM meteors have a similar sodium content to the components of the LEO and PER showers, suggesting a comet as a possible parent body. The sodium and magnesium content of the iron-class meteoroids is the lowest of all our samples, but it is not zero, suggesting that there are no pure iron meteoroids. The sodium content of the GEM meteor shower shows temporal variations in 2021 compared to the 2019 and 2020 observing seasons. We found no correlation between the sodium content and the perihelion distance for other meteor showers.