University, Department of Astronomy, P.O. Box 208101, New Haven, CT 06520-8101
Center for Relativistic Astrophysics (ICRA), University of Rome “La Sapienza”,
Physics Department, Piazzale Aldo Moro 5 00185, Rome, Italy
April 23, 2002
Abstract An analysis was done of the maxima of Mira Ceti, c Cygni, R Leonis, and R Hydrae, four Mira-type variable stars chosen
from among those studied by Argelander in 1839. A negative correlation between
the luminosity of consecutive maxima was found, except for R Hya. Mi+1 - Mivs.
Mi yields a correlation index of r2 = 0.6
for Mira and c Cyg, r2 = 0.44 for R Leo, and r2 = 0.25
for R Hya. Data analyzed range from the discovery of Mira (1596) to the present
time; they include AAVSO data, and there are from 90 (R Hya) to 179 (Mira Ceti)
pairs of consecutive maxima.