Spectroscopic and photometric observations of the short-period RS CVn-type star BH Virginis

Abstract

Abstract. High-resolution spectroscopic observations around the H α line and BVRI photometry from 1993 to 2003 of the eclipsing short-period RS CVn star BH Vir are presented. The simultaneous solution of our radial velocity curves and light curves yielded the following values for global parameters of the components:The measured rotational broadening of the spectral lines corresponds to equatorial velocities V 1 = 79.8 km s −1 and V 2 = 68.4 km s −1 . Our data reveal considerable H α emission excess of the two stellar components. We modelled the photometric data to find the size and location of the starspots for each year. The established decreasing trend of the spot latitudes may indicate a latitudinal cycle of at least a decade.

Active Longitudes in Close Binaries

“…The results again show spots on the primary, preferring the quadrature positions. The same results with spots at quadratures were acheieved for BH Vir for data starting in 1953 (Zeilik et al, 1990a;Kjurkchieva, et al, 2004), and for WY Cnc for data from 1964 onwards (Zeilik, 1990b;Heckert, 2001). UV Psc is composed of a main sequence and a subgiant component, or, just of two main sequence components, and similarly to the main sequence binaries it has spots at the quadratures Kjurkchieva et al, 2005).…”

Spectroscopic and Photometric Observations of the Short-Period RS CVn-Type Star UV Piscium

“…This feature is most likely the Ca i k6493.78 line similar to that found in the Sun; however, its profile in UV Psc is sufficiently wide and complex that our determination of the line center is imprecise. We also found orbital variability of this line in the short-period RS CVn stars CG Cyg (Kjurkchieva et al 2003a), ER Vul (Kjurkchieva et al 2003b), WY Cnc (Kjurkchieva et al 2004b), and BH Vir (Kjurkchieva et al 2004a). The 6493 8 line is almost as strong as H in the spectra of UV Psc.…”

“…For each of these systems, the secondary star is relatively cool (K or later spectral class) compared with the primary. In addition, the short-period RS CVn system BH Vir, which has two components close to the same spectral class, does not display similar secular variations from 1993 to 2003 (Kjurkchieva et al 2004a). Does the mechanism causing these secular variations require the secondary to be a late spectral class star?…”

Spectroscopic and photometric observations of the eclipsing star UV Leo

“…The line 6496 Å was the second strongest line of UV Leo in the observed spectral range 6470–6670 Å to show orbital variability. It also appeared in the spectra of all the short‐period RS CVn stars that we observed using the same equipment (Kjurkchieva, Marchev & Ogloza 2001; Kjurkchieva, Marchev & Zola 2002; Kjurkchieva, Marchev & Ogloza 2003a; Kjurkchieva, Marchev & Zola 2003b; Kjurkchieva et al 2004a; Kjurkchieva, Marchev & Ogloza 2004b; Kjurkchieva et al 2005). This line was identified as belonging to Ca i .…”