We have analyzed ~20,000
visual measures of the double-maximum Mira star R Centauri made by the AAVSO
and the RASNZ VSS during the past 72 years. Recently there has been a marked
change in the amplitude of variability and the shape of the light curve. The period
is also shortening at an increasingly fast rate. V and B-V
measures indicate that the first maximum is comparable to the maximum in
normal, single-peaked Mira stars.