Optical studies of transient low-mass X-ray binaries. IV. A 10-hour distorsion wave in the quiescent light curve of GS 2000+25.

摘要: We present new CCD photometric observations of QZ Vul, the optical counterpart very soft X-ray transient GS 2000+25, obtained during quiescent state in 1990 and 1991 Cousins I R bands a broad band (VR) covering λλ4700-7200 A region. Analysis this data combination with 1988 outburst reveals that single value orbital period, 8.25836±0.00012 h, accounts for all existing decay observations. The double-wave light curve, whose amplitude color signature are consistent what is expected from ellipsoidal shape dwarf G-K type companion, undergoes sine wave distortion 0.1 mag peak-to-peak 10.015±0.002 h period