Spectral energy distribution of a 3.3 M_⊙ stripped star and a 7.4 M_⊙ companion star (analogous to panel e of Fig. 7). We show underneath the plot of several photometrical filters in the UV and optical from GALEX, Swift and SDSS. These are discussed in Sect. 5.2 for detecting stripped stars via UV excess. We show a zoom-in of the optical spectrum where the composite spectrum is shown in purple. The HeII λ4686 emission line from the stripped star is visible in the composite spectrum. This line may be used for detecting stripped stars as discussed in Sect. 5.3.