The Venus synodic cycle is the 584-day rhythm between successive identical Sun-Venus alignments observed from Earth. Five of these cycles fit almost exactly into eight Earth years, which is why Venus traces a five-pointed star, the pentagram of Venus, across the zodiac over an 8-year arc. The pattern is a real orbital signature visible in the geocentric ephemeris.

Thirteen Venus orbits total about 2921.1 days, close to eight mean Earth years at about 2921.9 days. The Star Point return cadence comes from five Venus synodic periods, which total about 2919.6 days. Every 8 years Venus and the Sun therefore meet near the same zodiacal degree, drifting backward by roughly 2 to 3 degrees per cycle. Across decades the pentagram slowly rotates through the zodiac, which is why the active star points shift between signs across generations.

An inferior conjunction occurs when Venus passes between Earth and the Sun, with Venus retrograde at the moment of meeting. A superior conjunction occurs when Venus passes on the far side of the Sun, with Venus moving direct. The synodic cycle alternates between the two: inferior then superior then inferior again. Both event types meet at the same geocentric longitude. See the Venus cazimi page for the 17 arcminute solar proximity windows around those events.

The synodic cycle subdivides into eight named phases: New Venus (inferior conjunction), Morning Star Emerging, Morning Star Brilliant (greatest western elongation), Morning Star Descending, Full Venus (superior conjunction), Evening Star Emerging, Evening Star Brilliant (greatest eastern elongation), and Evening Star Descending. Each phase carries a distinct interpretive flavor. The Venus phase calculator classifies your natal phase and the current sky.

Same-star-point returns occur every ~8 years near the calendar anniversary of the prenatal conjunction: roughly ages 8, 16, 24, 32, 40, 48, 56, and 64. The 5th return at ~age 40 brings the same prenatal Star Point into the different chart context of midlife. The pentagram itself is traced inside each 8-year cycle by five successive conjunctions of the same type. The synodic return calculator lists the first eight returns with date and age.

Sun-Venus conjunctions are computed using the JPL DE440s planetary ephemeris via ANISE. The endpoint brackets each zero crossing in the Sun-Venus longitude difference, refines the crossing to an exact UTC instant, and computes both longitudes at that instant.

Each conjunction is classified as inferior or superior by checking Venus's apparent direction (retrograde or direct) near the conjunction. The pentagram drift, the 13:8 commensurability, and the Mayan Dresden Codex Venus tables all describe the same orbital signature from different observational and interpretive contexts.