On the chemical composition of the evolved very bright metal-poor star HD 1936

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ÇALIŞKAN TÜRKSOY Ş., Alazzawi J. M. K., Nasolo Y.

ASTRONOMISCHE NACHRICHTEN, vol.345, no.4, 2024 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 345 Issue: 4
  • Publication Date: 2024
  • Doi Number: 10.1002/asna.20230048
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, L'Année philologique, Aerospace Database, INSPEC, zbMATH
  • Keywords: chemical abundances, Galactic halo, metal-poor stars, stellar atmospheres
  • Ankara University Affiliated: Yes


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 18.35M(J). Although our study does not confirm or deny this, we briefly discuss the possibility of the star hosting a planet.