As we approach the festive period and look forward to enjoying the company of family and friends let us consider the potential astronomical origins of the ‘Christmas Star’. In Christian tradition the star indicated the direction in which the three wise men had to travel to discover the newly born king Jesus Christ. However, if we forget the religious nature of the stars appearance what astronomical events could explain this bright object appearing in the sky?

Many scholars have debated the actual birth date of Christ in order to determine what if any astronomical event could explain the appearance of such a bright object in the night sky. Unfortunately, there is no hard and fast date for the birth of Jesus Christ and as such makes life for astronomers very difficult indeed. However, if we look at the facts then some potential explanations could be offered.

First of all let us look at the three wise men or to give them they’re correct name Magi. The term Magi Pervasive throughout the Eastern Mediterranean and Western Asia until late antiquity and beyond, mágos, “Magian” or “magician,” was influenced by (and eventually displaced) Greek goēs (γόης), the older word for a practitioner of magic, to include astrology, alchemy and other forms of esoteric knowledge. If we take the term to mean astrologer or astronomer then they would have a very intimate knowledge of the night sky and able to predict several astronomical events that could explain the appearance of the star. One such explanation could be a planetary conjunction. These occur when two or more planets appear close to each other in the sky and in some instances can appear extremely bright.



In 1614, German astronomer Johannes Kepler determined that a series of three conjunctions of the planets Jupiter and Saturn occurred in the year 7 BC. He argued (incorrectly) that a planetary conjunction could create a nova, which he linked to the Star of Bethlehem. Modern calculations show that there was a gap of nearly a degree (approximately twice a diameter of the moon) between the planets, so these conjunctions were not visually impressive. An ancient almanac has been found in Babylon which covers the events of this period, but does not indicate that the conjunctions were of any special interest. In the 20th century, Prof. Karlis Kaufmanis, an astronomer, argued that this was an astronomical event where Jupiter and Saturn were in a triple conjunction in the constellation Pisces. Archaeologist and Assyriologist Simo Parpola has also suggested this explanation.
In 3–2 BC, there was a series of seven conjunctions, including three between Jupiter and Regulus and a strikingly close conjunction between Jupiter and Venus near Regulus on June 17, 2 BC. “The fusion of two planets would have been a rare and awe-inspiring event”, according to Roger Sinnott. Another Venus–Jupiter conjunction occurred earlier in August, 3 BC. These events however occurred after the generally accepted date of 4 BC for the death of Herod. Since the conjunction would have been seen in the west at sunset it could not have led the magi south from Jerusalem to Bethlehem. It also does not fit with an event seen at rising that might have started them on the journey.
Another alternative explanation is a visit from a Comet but these were usually seen as portents of doom. Halley’s Comet was visible in 12 BC and another object, possibly a comet or nova, was seen by Chinese and Korean stargazers in about 5 BC. This object was observed for over seventy days with no movement recorded. Ancient writers described comets as “hanging over” specific cities, just as the Star of Bethlehem was said to have “stood over” the “place” where Jesus was (the town of Bethlehem). The comet explanation has been recently promoted by Colin Nicholl. His theory involves a hypothetical comet which could have appeared in 6 BC.
Rare astronomical events such as a supernova has also been postulated by astronomers as a viable explanation. A recent (2005) hypothesis is that the star of Bethlehem was a supernova or hypernova occurring in the nearby Andromeda Galaxy. Although it is difficult to detect a supernova remnant in another galaxy, or obtain an accurate date of when it occurred, supernovae remnants have been detected in Andromeda.
The magi told Herod that they saw the star “in the East,” “at its rising”, which may imply the routine appearance of a constellation, or an asterism. One theory interprets the phrase in Matthew 2:2, “in the east,” as an astrological term concerning a “heliacal rising.” This idea was first proposed by Heinrich Voigt in 1911, a view rejected by Franz Boll (1867–1924). Two modern translators of ancient astrological texts insist that the text has nothing to do with either a heliacal or an acronycal rising of a star.

Lastly The Star of Bethlehem may have been connected to a series of unique, but largely discreet celestial events involving the planet Jupiter. One of the names used by the ancient Babylonian astronomers for Jupiter was MUL.BABBAR, meaning “the white star.” In this theory, special circumstances connected to Jupiter’s annual planetary cycle formed the backbone of the series of royal celestial signs. These events could have been symbolically associated with Judaism and the Messiah. This conception of the star has been referred to as “a serious study of what could have been a messianic Jewish perspective concerning the heavens two millennia ago.”

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