We present spectroscopy of the coma center of comet C/2020 F3 (NEOWISE), carried out at the end of July 2020 with the Échelle spectrograph FLECHAS at the University Observatory Jena. The comet was observed in five nights and many prominent emission features were detected between 4,685 and 7,376 Å. Beside the C₂ Swan emission bands also several emission features of the amidogen radical, as well as two forbidden lines of oxygen were identified in the FLECHAS spectra of the comet in all observing epochs. In contrast, strong sodium emission was detected only in the spectra of the comet, taken on 21 and July 23, 2020, which significantly faded between these two nights, and was no longer present in the spectra as of July 29, 2020. In this paper, we present and characterize the most prominent emission features, detected in the FLECHAS spectra of the comet, discuss their variability throughout our spectroscopic monitoring campaign, and use them to derive the radial velocity of the comet in all observing nights.

中文翻译：

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彗星 C/2020 F3 (NEOWISE) 的后续光谱

我们展示了彗星 C/2020 F3 (NEOWISE) 彗发中心的光谱，该光谱于 2020 年 7 月底在耶拿大学天文台使用阶梯光谱仪 FLECHAS 进行。这颗彗星在五个晚上被观测到，在 4,685 到 7,376 Å 之间检测到了许多突出的发射特征。在C ₂旁边在所有观测时期，在彗星的 FLECHAS 光谱中都发现了天鹅发射带和酰胺基自由基的几个发射特征，以及两条禁氧谱线。相比之下，仅在 2020 年 7 月 21 日和 23 日拍摄的彗星光谱中检测到强烈的钠发射，在这两晚之间显着减弱，并且在 2020 年 7 月 29 日的光谱中不再存在。在这篇论文中，我们展示并描述了在彗星 FLECHAS 光谱中检测到的最突出的发射特征，讨论了它们在整个光谱监测活动中的可变性，并使用它们来推导出所有观测夜晚彗星的径向速度。