Weird. A base 9 counting system? At first, I counted it off as octal (thinking z for zero), which seemed pretty reasonable, but then I realized my mistake.
Now I read the wiki article, and it's not even nonary.
It doesn't actually have a standard base at all; they seem to have discovered several times that there were more variable stars than they expected and had to extend the system in increasingly convoluted ways.
Now I read the wiki article, and it's not even nonary.