From the April 2009 issue

The constellation Ophiuchus lies partly on the ecliptic, so why isn’t it considered one of the zodiacal signs?

Steve Buckley, Johannesburg, South Africa
By | Published: April 27, 2009 | Last updated on February 1, 2024
Ophiuchus finder chart
The region of the sky associated with the astrological sign Scorpio includes stars from both Scorpius the Scorpion and Ophiuchus the Serpent Bearer. Surprisingly, the Sun spends more time in Ophiuchus even though it’s not among the 12 constellations of the astrological zodiac.
Astronomy: Roen Kelly

Ophiuchus is not part of the astrological zodiac because it first appeared in sky maps long after the Babylonians created the 12 signs and named them after constellations recognized at that time.