Evidence That HR 6990 Is a Spectroscopic Binary Hosting a Chemically Peculiar Late B-type star
Abstract
The archival IUE spectra of the late B giant HR 6990 are used to show that the absorption lines undergo large radial velocity variations in 2 spectra taken 4 months and 10 days apart. These large RV variations confirm that HR 6990 is a spectroscopic binary. The detection of strong lines of P II, Ga II, Ga III and Hg II show that the brightest member of the system, HR 6990 A, is not a normal late B-type giant but a newly discovered Chemically Peculiar star, probably a phosphorus and gallium enriched main sequence star. The two high resolution IUE spectra do not allow us to elucidate the nature of the companion, HR 6990 B.
- Publication:
-
Research Notes of the American Astronomical Society
- Pub Date:
- November 2020
- DOI:
- 10.3847/2515-5172/abc6ab
- Bibcode:
- 2020RNAAS...4..192M
- Keywords:
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- Chemically peculiar stars;
- Spectroscopic binary stars;
- 226;
- 1557