Abstract

The majority of hot subdwarfs lie on or close to the helium main-sequence. Many have hydrogen-rich surfaces, but a substantial fraction of the hotter subdwarfs have hydrogen-depleted or hydrogen-deficient surfaces. Amongst the former, three were known to show extraordinary overabundances of heavy elements including zirconium and lead. Using Subaru/HDS,we commenced a high-resolution survey of hydrogen-depleted subdwarfs to discover new members of the class. UVO 0825+15, was found to exhibit strong lead lines, to be an intrinsic variable in K2 field 5, and to have a relatively high space motion. Two other lead-rich subdwarfs have been found in the Subaru sample. A much wider survey is in progress using SALT/HRS. Discoveries so far include one extreme helium star similar to V652 Her, and an intermediate helium star with possible comparison to HD144941. Analyses of the hotter and more compact members of the sample are continuing. Open Access.

Document Type

Article

DOI

https://doi.org/10.1515/astro-2017-0439

Rights Information

© 2017 the authors. Published by DeGruyter Open. This work is licensed underthe Creative Commons Attribution NonCommercial-NoDerivatives 4.0 License.

Keywords

stars: chemically peculiar, stars: subdwarfs

Publication Date

12-20-2017

Journal Title

Open Astronomy

Download

Share

COinS