An anticorrelation between X-ray luminosity and Hα equivalent width in X-ray binaries
We report an anticorrelation between continuum luminosity and the equivalent width (EW) of the Hα emission line in X-ray binary systems. The effect is evident...
An atlas of optical continuum and line emission from low-mass X-ray binaries
We have obtained broad-band optical spectra of a sample of 15 low-mass X-ray binaries (LMXBs) in the range 4000-9000A and fitted them with combinations of...
An ellipsoidal modulation in Nova Ophiuchi 1977 (=H1705-25=V2107 Oph)
We report the detection of an orbital, ellipsoidal modulation at a period of 16.8h for V2107 Oph (Nova Ophiuchi 1977, H1705-25), from R-band photometry. From...
An ellipsoidal modulation in X-ray Nova VELA 1993 (=GRS 1009-45)
We present the first optical observations of the soft X-ray transient Nova Vela 1993, taken during quiescence in 1995 and 1996. From the R-band photometry with...
An equatorial outflow in the black hole optical dipper Swift J1357.2-0933
We present high time resolution optical spectroscopy and imaging of the black hole transient Swift J1357.2-0933 during its 2017 outburst. The light curves show...
An evolved donor star in the long-period cataclysmic variable HS 0218+3229
Context: We present time-resolved spectroscopy and photometry of HS 0218+3229, a new long-period cataclysmic variable discovered within the Hamburg Quasar...
An Evolving Compact Jet in the Black Hole X-Ray Binary MAXI J1836–194
We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836–194 over state transitions during its discovery...
An infrared FWHM-K<SUB>2</SUB> correlation to uncover highly reddened quiescent black holes
Among the sample of Galactic transient X-ray binaries (SXTs) discovered to date, about 70 have been proposed as likely candidates to host a black hole. Yet...