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When Was Jesus Born? The Star of Bethlehem

Early patristic sources suggest Jesus was born around 3 or 2 BC. Such a date is plausible if Herod died in 1 BC‚ a view that can be supported from a careful reading of Josephus‚ and if the “Christmas census” is interpreted as an empire-wide oath of allegiance on the occasion of Augustus’ jubilee year. If this is indeed the correct time frame, how might we interpret the star of Bethlehem? In this post I’ll suggest a relatively new interpretation of the astronomical data.

Interpreting the Star Astronomically

Assuming the star of Bethlehem was a natural occurrence that later acquired a spiritual significance (rather than being a miracle in its own right), many scholars equate this phenomenon with a Jupiter-Saturn conjunction of around 7 BC. Recently, however, Ernest Martin has proposed another option related to a series of astronomical events occurring between May of 3 BC and December of 2 BC. Two Jupiter-Venus conjunctions frame the time period under consideration:

  • August 12, 3 BC: Jupiter-Venus conjunction in the morning, in the constellation Cancer (the concluding sign of the astrological year). This was the date of the heliacal rising of Jupiter (that is, rising in the morning at the same time the sun does) and on the first day of the new moon, Ellul 1, AM 3758. Note that the Magi claimed, “we have seen his star at its rising” (Mt 2:2).
  • June 17, 2 BC: a Jupiter-Venus conjunction in the evening, in the constellation Leo (the beginning sign of the astrological year and the “royal constellation”), at the precise time of the full moon. In commonly understood astrological symbolism, these two conjunctions would have signified the close of one age of history and the beginning of another.

Between these two conjunctions, Jupiter came into conjunction three times with Regulus, the “royal star,” in the constellation Leo. This signified the royal planet in conjunction with the royal star within the royal constellation! These conjunctions occurred on the following dates:

  • September 14, 3 BC.
  • Feb 17, 2 BC: After stopping in its path on Dec 1, 3 BC and beginning its annual retrogression, Jupiter again moved into conjunction with Regulus on this date.
  • May 8, 2 BC: After once again heading forward, Jupiter and Regulus came into conjunction on this date for the third time in eight months.

The three conjunctions together made it look like Jupiter has circled over and around Regulus, “highlighting” the king star by tracing a “crown” above it. Some additional astronomical events occurred in this time period:

  • May 19, 3 BC: Saturn and Mercury in close conjunction.
  • June 12, 3 BC: Saturn and Venus in close conjunction.
  • Apr 30, 2 BC: Jupiter, Mars, Venus, and Mercury amassed in a close longitudinal relationship (once again in the constellation Leo), signifying a new beginning in historical affairs.

There is another aspect of this interpretation that I don’t believe Martin has noted. Nearly every astronomically significant date in this theory has some connection to the Jewish festival calendar:

  • The September 14, 3 BC Jupiter-Regulus conjunction falls halfway between Rosh Hashanah (September 10/Tishrei 1, AM 3759) and Yom Kippur (September 19/Tishrei 10, AM 3759).
  • The February 17, 2 BC Jupiter-Regulus conjunction coincides with the date of Purim (Adar 14, AM 3759).
  • The May 8, 2 BC Jupiter-Regulus conjuction falls on the date of Shavuot (Sivan 6, AM 3759)
  • The June 12, 2 BC Jupiter-Venus conjunction took place on the evening of Tammuz 17, AM 3759. In later times, this date ushered in a three-week period of fasting leading up to the 9th of Av.

I doubt there is much to be made of all this, but it is interesting even so.


A date between mid-May 3 BC and mid-June 2 BC would correspond with a notable series of astronomical events which may well have been interpreted by the Magi as signs of the birth of a king and the beginning of a new historical era. This date range is a very close fit with patristic testimony about the year of Jesus’ birth.

Is it possible, however, to narrow the time frame even more?

Next: The Date of Jesus’ Birth?

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