1 INTRODUCTION  
2 M.-S. Hernandez et al.  
2 OBSERVATIONS  
2.1 Optical high resolution spectroscopy  
2.2 HST spectroscopy  
2.3 TESS photometry  
3 STELLAR AND ORBITAL PARAMETERS  
3.1 The secondary stars  
3.2 Radial velocities  
3.3 Photometric observations  
3.4 The white dwarfs  
4 SCRUTINIZING THE UNUSUAL EMISSION LINES IN TYC 110-755-1  
5 PAST AND FUTURE EVOLUTION  
6 CONCLUSIONS