We present the classification of 26 optical counterparts to X-ray sources discovered in the Galactic Bulge Survey .
We use ( time-resolved ) photometric and spectroscopic observations to classify the X-ray sources based on their multi-wavelength properties .
We find a variety of source classes , spanning different phases of stellar/binary evolution .
We classify CX21 as a quiescent cataclysmic variable ( CV ) below the period gap , and CX118 as a high accretion rate ( nova-like ) CV .
CXB12 displays excess UV emission , and could contain a compact object with a giant star companion , making it a candidate symbiotic binary or quiescent low mass X-ray binary ( although other scenarios can not be ruled out ) .
CXB34 is a magnetic CV ( polar ) that shows photometric evidence for a change in accretion state .
The magnetic classification is based on the detection of X-ray pulsations with a period of 81 \pm 2 min .
CXB42 is identified as a young stellar object , namely a weak-lined T Tauri star exhibiting ( to date unexplained ) UX Ori-like photometric variability .
The optical spectrum of CXB43 contains two ( resolved ) unidentified double-peaked emission lines .
No known scenario , such as an AGN or symbiotic binary , can easily explain its characteristics .
We additionally classify 20 objects as likely active stars based on optical spectroscopy , their X-ray to optical flux ratios and photometric variability .
In 4 cases we identify the sources as binary stars .