We present chemical abundances of the very bright metal-poor star HD 1936 based on high-resolution and high SNR spectra from AUKR. We obtain the abundances of 29 atomic species with atomic numbers between 3 and 63. In this context, the derived lithium abundance of 1.01 is consistent with the thin Li plateau observed in lower red giant branch stars. The star is a carbon-normal with a ratio of −0.31, just like other low-luminosity red giants on the thin Li plateau. We find the ratios of [Eu/Fe] = 0.43 and [Ba/Eu] = −0.64, indicating very little s-process contamination. These ratios allow us to classify the star as a moderately r-process-enhanced (r-I) metal-poor star for the first time. It is worth mentioning that the star has a metallicity of −1.74, a [Cu/Fe] of −0.74, a [Zn/Fe] of 0.04, and a [Mg/C] of 0.69. The results suggest that it may be a second-generation star formed in a multi-enriched environment, rather than being a descendant of very massive first-generation stars. A last point worth mentioning is the possibility that HD 1936 may host a sub-stellar component with a mass of . Although our study does not confirm or deny this, we briefly discuss the possibility of the star hosting a planet.

中文翻译：

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关于演化后的极亮贫金属恒星 HD 1936 的化学成分

我们根据 AUKR 的高分辨率和高 SNR 光谱展示了非常明亮的贫金属恒星 HD 1936 的化学丰度。我们获得了原子序数在 3 到 63 之间的 29 个原子种类的丰度。在这种情况下，导出的锂丰度 1.01 与在较低的红巨星分支恒星中观察到的薄锂平台一致。这颗恒星是碳正态恒星，比率为-0.31，就像薄锂高原上的其他低光度红巨星一样。我们发现比率 [Eu/Fe] = 0.43 和 [Ba/Eu] = -0.64，表明 s 过程污染非常少。这些比率使我们首次将这颗恒星归类为中度r过程增强（rI）贫金属恒星。值得一提的是，该恒星的金属丰度为-1.74，[Cu/Fe]为-0.74，[Zn/Fe]为0.04，[Mg/C]为0.69。结果表明，它可能是在多重丰富环境中形成的第二代恒星，而不是非常巨大的第一代恒星的后代。最后值得一提的是，HD 1936 可能拥有一个质量为。尽管我们的研究没有证实或否认这一点，但我们还是简要讨论了这颗恒星存在行星的可能性。