XX Leo See also Michele's XX Leo Page Data taken March-May 1997. The period, at least during the last 25 years, seems consistent with .97113 days. The horizontal line at 0 represents the middle of the primary minimum. The line at .5 is of course then the secondary minimum. The vertical dashed lines represent midnight Jan 1 in 1980 and 1990.
Symbols represent observation methods.
It has been suggested based on two much earlier observations the period might have been closer to .97094 days. But as the later data seems to conflict with this, and there isn't very much data from the very earlier times, I am skeptical. The vertical dashed lines again represent Jan 1 dates at beginning of each decade 1950 to 1990.