Late B-type Stars with Inflated Hot Subdwarf Companions

In recent years, interest has grown in hot subdwarf stars that originate from intermediate and massive stars because only a few of them are known albeit their numerous prediction. However, observing these stars is quite a challenge because most of them are part of binaries where the mostly Be type companions are outshining them. Hot subdwarfs around Be type stars were discovered in the UV range of Hubble but these observations are expensive and difficult to obtain. Recently, prominent discoveries of massive black holes turned out to be bloated stripped stars that are believed to still contract towards the helium main sequence. These systems mark a very short period in binary star evolution and provide a very rare opportunity to directly observe the hot subdwarf. The only known late B type star with a hot subdwarf is HD 133729 and in this system the sdB is a blue large amplitude pulsator (BLAP). In our effort to deredden the galactic disk to identify more hot subdwarf candidates we stumbled across new late B star systems that seem to have hot subdwarf companions. In my talk, I will explain our dereddening method and present preliminary results on the newly discovered B star systems.