High-resolution H spectroscopy of the bright RS CVn system HR 7275
Articles > Article · 1989
Authors: Z. Eker
Monthly Notices of the Royal Astronomical Society, International, 1989, vol 238, pp 675-688
Summary
HR 7275 is a bright, long-period (28 day), single-lined RS CVn binary. High-resolution (0.36 Å) and good signal-to-noise ratio (S/N ∼ 150) echelle spectra do not show any clear evidence of the secondary in the system on spectral lines. Also, absence of a continuum on a low-resolution UV spectrum (IUE merged log) and the known mass function imply a main-sequence secondary with a spectral type late F to middle G, corresponding to the mass range of |$0.9\lt M_2 \lt 1.1\enspace M_\odot$|. This corresponds to a |$1\lt M_1 \lt 1.5\enspace M_\odot$| mass range for the primary. The present spectra show variable Hα from the primary (K 1 III–IV). At least 30 per cent excess emission with respect to Arcturus and about 7 per cent modulation of the central intensity in the term of continuum at Hα has been measured. The maximum emission occurred during light minimum on the light curve of the same cycle (Seeds & Nations) of present observations.