Abstract. We present dynamic (22 frames per second) observations of optical spectra of small-mass (2–200 mg) meteors observed with an EMCCD imager equipped with a diffraction grating. This observational campaign occurred at Arecibo, Puerto Rico during May 2012, resulting in eight hours of clear data over four nights. We detected 22 meteors with this setup and their spectra showed varying compositions, including evidence of Na, Mg, Fe, and Ca. Spectral lines persisting over multiple frames (up to 23 frames) with sufficient signal, showed evidence for differential ablation. Brighter, more massive meteors had stronger and varied spectral signals, which showed that the temporal and spectral resolution of the faintest meteors approached the noise level of the camera system. Optical and spectral detections of these small-mass meteors provide a greater understanding of the composition of the milligram-sized population of meteors.

中文翻译：

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小质量流星的动态光谱

摘要。我们展示了动态（以每秒22帧的速度）观测到的小质量（2-200 mg）流星的光谱，这些流星是由配备有衍射光栅的EMCCD成像仪观察到的。这项观测活动于2012年5月在波多黎各的阿雷西博进行，导致了四个晚上的八个小时的清晰数据。我们用这种设置检测到22个流星，它们的光谱显示出不同的组成，包括Na，Mg，Fe和Ca的证据。频谱线在具有足够信号的多个帧（最多23帧）上持续存在，显示了差异消融的证据。亮度更大，质量更大的流星具有更强和变化的光谱信号，这表明最暗的流星的时间和光谱分辨率接近相机系统的噪声水平。