Delimitation Scientifique des Constellations

Eugene Delporte's work is the International Astronomical Union's own adopted 1930 constellation boundaries, the technical document that fixed the precise borders astronomers still use today, including the specific fact that these boundaries put the ecliptic through thirteen constellations rather than the twelve of tropical astrology. Its authority rests on institutional adoption by the professional body that governs astronomical nomenclature, a checkable, documented act of standardization rather than a claim resting on Delporte's personal reputation. Use it to establish the modern scientific constellation boundaries and which constellations the ecliptic actually crosses; it is not a source for the mythological content or traditional meaning of any constellation, which needs a separate source.