posted January 22, 2012 01:47 PM
Arabic parts are calculated points, which emphasize / describe the relationship between certain planets, usually including Sun and ASC.The part of Eros as it appears in astro.com is actually derived by two other Arabic parts; the part of Spirit and the part of Fortune, which are interrelations between ASC, Sun and Moon in a chart.
The arabic parts have different calculations for night and day births.
For a day birth (Sun in houses 7 to 12):
the part of fortune:
ASC + Moon - Sun
the part of Spirit:
ASC + Sun - Moon
The part of Eros:
ASC + part of Spirit - part of Fortune
With night births the calculation is reversed.
Unlke the arabic parts, which are calculated points, the asteroid Eros is a physically existing object int he sky, an asteroid.