Bibcode
Casares, J.; Charles, P. A.; Marsh, T. R.
Bibliographical reference
Unknown
Advertised on:
1
1995
Citations
0
Refereed citations
0
Description
We report the spectroscopic detection of the secondary star in the x-ray
transient QZ Vul (=GS 2000+25). Cross-correlation of individual spectra
against K-type templates yields clear velocity modulations with the 8.3
hr orbital period. From the amplitude of the radial velocity curve (520
+/- 16 km/s) we derive a mass function f(M)= 5.02 +/- 0.46 solar mass,
the second largest after V404 Cygni. We classify the companion star as a
K5+/-2 V which is the dominant light source in our spectral range
(lambda lambda 6000-8800). Doppler imaging of the broad H-alpha emission
shows evidence for an intense hot spot from which we estimate an
accretion disc radius of 0.47 +/- 0.03 RLx.