We have identified five new R Coronae Borealis ( RCB ) stars in the Galactic bulge using the MACHO Project photometry database , raising the total number of known Galactic RCB stars to about 40 .
We have obtained spectra to confirm the identifications .
The fact that four out of the five newly identified RCB stars are “ cool ” ( T _ { eff } < 6000 K ) rather than “ warm ” ( T _ { eff } > 6000 K ) suggests that the preponderance of warm RCB stars among the existing sample is a selection bias .
These cool RCB stars are redder and fainter than their warm counterparts and may have been missed in surveys done with blue plates .
Based on the number of new RCB stars discovered in the MACHO bulge fields , there may be \sim 250 RCB stars in the reddened “ exclusion ” zone toward the bulge .