the so far high cadence of spectra enables very well the determination of the exact time of the last periastron (important to determine the orbital period of the companion). Thanks a lot to all the colleagues who contributed so far!!
But in order to evaluate the total character of the periastron passage with parameter EW, V/R, RV and CA (= central absorption core) of the Halpha line profile, further spectra are urgently required.
Please try it, if it is possible ...