GS 2000+25 is an X-ray binary system in the constellation Vulpecula, consisting of a late K-type star and a black hole. It is also an X-ray nova. Because the black hole is more massive than …

within arcsec The VizieR photometry tool allows for easy visualization of photometry points extracted around the Simbad position from photometry-enabled catalogues in VizieR. The …

We present new CCD photometric observations of QZ Vul, the optical counterpart of the very soft X-ray transient GS 2000 + 25, obtained during the quiescent state in 1990 and 1991 in the …

QZ VULPECULAE P. A. Charles and J. Casares, Oxford University, write: "Optical spectroscopy of QZ Vul obtained with the 4.2-m William Herschel Telescope on La Palma shows broad …

Nov 15, 1999 · We have used GRIM II on the ARC 3.5 meter telescope at Apache Point Observatory to obtain infrared photometry of GS2000+25 (QZ Vul). By modeling the SXT …

Feb 28, 1993 · We present new CCD photometric observations of QZ Vul, the optical counterpart of the very soft X-ray transient GS 2000 + 25, obtained during the quiescent state in 1990 and …

The mass of the black hole in GS 2000 + 25 ( = QZ Vul) Abstract: We report the first infrared light curve of GS 2000 + 25. By modelling the brightness variations as ellipsoidal modulations of …

QZ Vul thus has the second largest mass function known amongst the blackhole x-ray binaries, after V404 Cyg (Casares and Charles 1994, MNRAS 271, L5)."

Oct 31, 1995 · We report the first spectroscopic detection of the secondary star in the X-ray transient QZ Vul (=GS 2000+25). Cross-correlation of individual spectra against K-type …

By modelling the brightness variations as ellipsoidal modulations of the secondary star, the authors find the mass of the compact object to lie between 4.8 and 14.4 M sun (90 per cent …