Discovery of two FK Comae stars in the southern hemisphere
Abstract
Radial velocity measurements, high resolution Hα spectra and broad band photometry are presented for two late G - early K southern giant stars, HD 32918 and HD 36705. Both stars are nown Ca II emitters; the high rotational broadening found in their spectra (Ve sin i > 50 km s-1) and lack of evidence for any radial velocity variations indicates that they are members of the FK Comae class of fast-rotating surface-active late-type giants. Photometry of HD32918 shows an RS CVn-like distortion wave with an amplitude of 0.3 mag in V, and a period of 9.55 days. Variable Hα emission is present in both stars. The space density of FK Comae stars is discussed; the results are broadly consistent with the hypothesis that the FK Comae stars represent a stage in the post-main-sequence evolution of W Ursae Majoris systems.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 1982
- DOI:
- 10.1093/mnras/200.3.589
- Bibcode:
- 1982MNRAS.200..589C