Abstract Sodium is a perfect indicator to investigate the volatility within meteoroid composition. Spectroscopic observations of the Geminid meteors were carried out using modern high sensitive large format CMOS cameras. 149 visible spectra of the Geminid meteors observed in 2017 and 2018 were analyzed by a newly developed procedure. The variation of Na, Mg and Fe during meteor ablation in the atmosphere has been studied. Although sodium is depleted in ~ 80% of the Geminids, statistically significant variations of sodium in the Geminid meteors were found. It should be noted that Na depletion in the Geminid meteors increased with decreasing meteoroid size. A yearly variation of Na in the Geminid meteor streams was also found. Solar-heating age across the different parts of the meteoroids stream ejected from a parent active asteroid (3200) Phaethon having 0.14 AU small perihelion distance seems to the most likely explanation for the sodium variation and depletion. Surprisingly, three iron Geminid meteors were detected across the maximum of 2018 Geminids.

中文翻译：

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来自 (3200) phaethon 的双子座流星体的钠变化

摘要 钠是研究流星体成分波动性的完美指标。双子座流星的光谱观测是使用现代高灵敏度大画幅 CMOS 相机进行的。通过新开发的程序分析了 2017 年和 2018 年观测到的双子座流星雨的 149 个可见光谱。已经研究了大气中流星消融过程中 Na、Mg 和 Fe 的变化。尽管大约 80% 的双子座流星雨中的钠已经耗尽，但在双子座流星雨中发现了钠在统计上的显着变化。应该指出的是，双子座流星中的 Na 消耗随着流星体尺寸的减小而增加。还发现了双子座流星流中 Na 的年度变化。从具有 0.14 AU 小近日点距离的母体活动小行星（3200）Phaethon 喷出的流星体流不同部分的太阳加热年龄似乎是钠变化和消耗的最可能解释。令人惊讶的是，在 2018 年最多的双子座流星雨中发现了三颗铁质双子座流星雨。