Spectroscopic observations of the short-period, RS CVn-type star SV Cam

Abstract

Abstract. Spectroscopic observations of the eclipsing, short-period RS CVn-star SV Cam in the range 6500-6700Å, covering the whole orbital period are presented. The absorption profiles of the lines Hα and FeI 6678 are doubled out of the eclipses. The relative contribution of the secondary star is stronger in the FeI 6678 line than in Hα. We determined K1 = 123.1 ± 1.2 km s and V 2 eq = 79 km s −1 corresponding to the measured rotational broadenings of the investigated lines coincide with the velocities calculated from the obtained stellar radii. The phase behavior of both Hα and FeI 6678 profiles of the primary star shows the presence of two cool spots with maximum visibilities at phases 0.27 and 0.86. The analysis of the two lines in the middle of the primary eclipse allows us to illustrate the excess of the Hα emission of the secondary star. The parameters of the stellar components of SV Cam derived from our spectroscopy and photometry are in very good agreement. The final result of our investigation is that there are three sources of activity in SV Cam: local active regions (photospheric spots) on its primary component, enhanced chromospheric emission from the secondary star and some additional emission originating from circumstellar gas.

Spectroscopic and photometric observations of the short-period RS CVn-type star ER Vulpeculae

“…We determined the rotational broadenings of the H α and FeI 6594 lines for ER Vul with the same method as that used for SV Cam (Kjurkchieva et al 2002), i.e. fitting the central parts of their profiles by 6th-order polynomial and measuring the half width of these fits at the continuum level.…”

Astrophysics in 2002

“…They still have it (Gu et al 2002), and it is often spotty (Fransca et al 2002). Indeed there can be activity from each star separately and from the gas in between (Kjurkchieva et al 2002), which brings us to one last activity point.…”

H$\mathsf{_{\alpha}}$ observations of the star FK Com

“…It has symmetric shape with constant depth, width and λ position. This line has a FWHM around 7 Å and rotational broadening of about 4.2 Å (determined by fitting the central parts of the profiles with 6th-order polynomials and measuring the half width of these fits at the continuum level, Kjurkchieva et al 2002) (Eaton 1990); 200 km s −1 (Walter et al 1984); 162.5 ± 3.5 km s −1 (Huenemoerder et al 1993). The different width of the spectral lines of FK Com means that they originate from different layers of the stellar atmosphere.…”