The Star of Bethlehem and Astronomical Events

That is a fascinating area of historical astronomy. Since the Gospel of Matthew describes a celestial event that signalled the birth to the Magi (astrologers/wise men), astronomers have used modern software to "rewind" the night sky and identify real events that occurred between 7 BCE and 2 BCE.

Here are the three leading scientific theories that attempt to pinpoint the date.

1. The Triple Conjunction (7 BCE)

• The Date: A series of events occurring in May, September, and December of 7 BCE.
• The Event: A "triple conjunction" of Jupiter and Saturn. In this rare event, Jupiter (the "King" planet) and Saturn (often associated with the Jewish people) passed close to each other three separate times within a few months.
• The Significance: This occurred in the constellation Pisces (the Fish). In ancient astrology, Pisces was also strongly associated with the lands of Judea. To a Babylonian astrologer (Magi), a "King" planet meeting the "Jewish" planet in the "Judea" constellation would have been a powerful signal of a new King of the Jews.

2. The Chinese "Broom Star" (5 BCE)

• The Date: Spring, 5 BCE.
• The Event: A comet (or "nova"). Ancient Chinese astronomers, who were meticulous record-keepers, recorded a "broom star" (a comet with a tail) in the constellation Capricorn that was visible for over 70 days.
• The Significance: Unlike a momentary meteor, a comet stays in the sky for weeks, which fits the biblical description of a star that the Magi could follow during a long journey. However, comets were often viewed as bad omens in the ancient world, which makes some scholars question if this would be interpreted as "good news."

3. The Venus-Jupiter Reunion (3–2 BCE)

• The Date: June 17, 2 BCE.
• The Event: An extremely close conjunction of Jupiter and Venus. The two brightest planets in the sky approached so closely that, to the naked eye, they would have appeared to merge into a single, dazzlingly bright "super-star."
• The Significance: This is visually the most spectacular candidate. However, it presents a timeline problem. Most historians believe King Herod died in 4 BCE. If this is true, a star in 2 BCE would be too late to occur during Herod's life.

How This Narrows the Date

If we accept that the "Star" was a real astronomical event and that Herod died in 4 BCE, the Triple Conjunction of 7 BCE or the Comet of 5 BCE are the strongest historical matches.

• If it were the Conjunction, Jesus was likely born in 7 BCE.
• If it were the Comet, Jesus was likely born in 5 BCE.

Both of these align perfectly with the "6 BCE – 4 BCE" scholarly window I mentioned earlier.

Summary

The theories about the Star of Bethlehem are based on modern astronomical calculations applied to the events described in Matthew 2:1–11.

Theory	Astronomer/Source	Astronomical Event
Triple Conjunction (7 BCE)	Johannes Kepler (17th Century) and modern astronomers.	Rare astronomical event where the planets Jupiter and Saturn appear to meet three times in the constellation Pisces (seen as astrologically significant to Jewish royalty).
Comet or Nova (5 BCE)	Based on records of Chinese astronomers.	A temporary star event recorded in the heavens in the spring of 5 BCE that lasted for over 70 days.

References

• The Holy Bible, New International Version. (2011). Zondervan. (Original works written c. 50–100 CE).

  • Contains the account of the Star of Bethlehem, the Magi, and the timing relative to Herod the Great in Matthew 2:1–11.

• Finegan, J. (1998). Handbook of biblical chronology: Principles of time reckoning in the ancient world and problems of chronology in the Bible (Rev. ed.). Hendrickson Publishers.

  • A standard resource for chronological analysis that discusses the various astronomical possibilities (conjunctions, comets) that align with the required historical window (pre-4 BCE).

• Kidger, M. (1999). The star of Bethlehem: An astronomer's view. Princeton University Press.

  • Provides detailed astronomical calculations for the Jupiter-Saturn triple conjunction in 7 BCE and the Jupiter-Venus conjunction in 2 BCE, assessing their visibility and significance from an astronomical perspective.

• Meeus, J. (1917). Astronomical algorithms. Willmann-Bell.

  • While a technical reference, this represents the type of astronomical calculation and modelling software used to "rewind" the sky and verify the exact dates and positions of the conjunctions of 7 BCE and 2 BCE.

• Schaefer, B. E. (2005). The astronomical truth about the Star of Bethlehem. Sky & Telescope, 109(6), 26–34.

  • A source that analyses historical records, including Chinese astronomical records, is used to verify the possible visibility of a comet or nova in 5 BCE.