The three decans of each sign are associated with traits which strengthen or vary the essential characteristic of the astrological Sun sign.
To apply this, you will need to know the degree your Sun was in at birth.²
For illustration, if you were born with an Aries Sun, this is a Fire sign.
Born 0 to 9 degrees 59 minutes & 59 seconds Aries is the first Decan ruled by Mars. This is the most dynamic, independent of all the Aries decans. Enthusiastic, impulsive, you would like to live life to its fullest, adventuring out in the world or within your mind.
Born 10 to 19 degrees 59 minutes & 59 seconds Aries is the second Decan ruled by the Sun. Strong on self-confidence, generous, noble minded, you are ambitious, single minded yet principled.
Born 20 to 29 degrees 59 minutes & 59 seconds Scorpio is the third Decan ruled by Jupiter. Add a love of adventure & enthusiasm to the individualism of Aries, along with expanding your intellectual knowledge & experience.
Decans can be applied to each of the planets & angles of your chart. They provide yet another way to further understand yourself & your unique nature.
¹ Also known as Decantes. ² If you would like to learn your Sun sign Decan, contact me.