  R Coronae Borealis stars (RCBs) are rare, hydrogen-deficient, carbon-rich
supergiant variable stars that are likely the evolved merger products of pairs
of CO and He white dwarfs. Only 55 RCB stars are known in our galaxy and their
distribution on the sky is weighted heavily by microlensing survey field
positions. A less-biased wide-area survey would provide the ability to test
competing evolutionary scenarios, understand the population or populations that
produce RCBs and constraint their formation rate. The ASAS-3 survey monitored
the sky south of declination +28 deg since 2000 to a limiting magnitude of
V=14. We searched ASAS-3 for RCB variables using a number of different methods
to ensure that the probability of RCB detection was as high as possible and to
reduce selection biases based on luminosity, temperature, dust production
activity and shell brightness. Candidates whose light curves were visually
inspected were pre-selected based on their infrared excesses due to warm dust
in their circumstellar shells using the WISE and/or 2MASS catalogues, and
criteria on light curve variability. We then acquired spectra of 104 stars to
determine their real nature using the SSO/WiFeS spectrograph. We report 21
newly-discovered RCB stars and 2 new DY Per stars. Two previously suspected RCB
candidates were also spectroscopically confirmed. Our methods allowed us to
extend our detection efficiency to fainter magnitudes that would not have been
easily accessible to discovery techniques based only on light curve
variability. The overall detection efficiency is about 90% for RCBs with
maximum light brighter than V~13. This growing sample is of great value to
constrain the peculiar and disparate atmosphere composition of RCBs. Most
importantly, we show that the spatial distribution and apparent magnitudes of
Galactic RCB stars is consistent with RCBs being part of the Galactic bulge
population.
