Alpha Kratonii was a star system located near Starbase 86, somewhere in the space of the galaxy's Alpha or Beta Quadrants. This system was home to a string of mining colonies. (TOS novel: The Better Man)

The stellar notation using the Greek language letter "alpha" indicates that there might be a star group or constellation of some sort named "Kratonii", of which Alpha Kratonii would logically be indicated to be the most prominent star or system.