SEPARATING THE SPECTRA OF BINARY STARS .1. A SIMPLE METHOD - SECONDARY RECONSTRUCTION

We present a practical method for the analysis of spectroscopic binari es, reconstructing the lines of the two components of the system. We s how that the problem of the separation of binary spectra can be solved in an easy way, under most common conditions. One pair of observation s may be sufficient, if taken at different orbital phases of the syste m, preferably at opposite quadratures. The separation procedure is dis cussed analytically, and a technique is described, which allows to res tore the secondary lines in few steps. An algorithm is also provided, which derives the radial velocity of the secondary star, by directly a nalysing a difference line-profile obtained from the two input spectra . The efficiency of the method is tested, by reconstructing artificial line-profiles and simulated binary spectra as well. Then the procedur e is applied to the eclipsing binary IZ Per, revealing for the first t ime its faint secondary spectrum.