Star of wonder: What was the bright light that drew the Magi to Bethlehem?

David Whitehouse believes he has the answer and that we should be celebrating Christmas in September

"In the time of King Herod, after Jesus was born in Bethlehem of Judea, wise men from the East came to Jerusalem, asking, where is the child who has been born king of the Jews? For we observed his star at its rising, and have come to pay him homage." Gospel of St Matthew

What was it that summoned the Magi to make a long and dangerous journey to a foreign land? What was this star and its urgent message? The clues can be found in one of the Gospels and in other religious texts of the time that also describe the birth of Jesus as well as in the words of medieval monks and astronomers. Two thousand years ago only the Wise Men saw it, but if you solve the clues then anyone with a computer and a simple starmap program can witness the Star of Bethlehem.

The Star is only mentioned in the Gospel of St Matthew, though the Gospel of St Luke also gives an account of the birth of Christ. Why is there is no mention of the star in Luke? Although Mark is the earliest Gospel and provides much of the material for both Matthew and Luke, depicting Jesus as a man and the son of God, it is Matthew's Gospel with the aim of proclaiming Jesus as the fulfilment of ancient prophecy that is taken as the first one because it provides a bridge between the Old and New testaments.

But the Star is not only mentioned in the Bible. There is a non-biblical text of the time called the Protoevangelium of St James. In it the description of the star is very different; "And the wise men said; 'We saw how an indescribably greater star shone among these stars and dimmed them so that they no longer shone.' "

The explanation for the difference may lie with the need for the writer of the Protoevangelium to associate the Messiah with a great star. For centuries rebel leaders and self-proclaimed Messiahs were said to have their own star signifying divine approval. In the second century AD, for example, the rabbi Aquiba proclaimed Simeon Bar Kosba as the Messiah. Kosba then changed his name to Simeon Bar Kokhba meaning "son of a star". So the writer of the Protoevangelium may have thought, no great star, no Messiah. It therefore provides little in the way of definite clues.

The Bible gives us an indication to the date. The reason why Joseph and Mary travelled from Nazareth to Bethlehem was the census decreed by Emperor Augustus around 8BC. The star and Jesus's birth must have occurred about that time.

It is significant that the arrival of the Magi came as a great surprise to Herod and his advisors, suggesting they had not seen the star, which seemingly rules out a brilliant light as stated in the Protoevangelium. Yet the Magi saw it and undertook a journey of perhaps a thousand miles. Upon reaching Jerusalem they were told of the prophecy of Micah. "But thou, Bethlehem Ephratah, though thou be little among the thousand of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel."

Another important clue is that the Magi saw the star in the east. Some scholars believe this to be an error in translation from "en te anatole", which is a phrase that has a special astronomical significance. It means that the star was up all night rose at sunset and set at sunrise one of the five principal astrological positions of the Babylonians when a celestial body was thought to have its maximum influence on worldly events.

As is well known, Herod sent the Magi to Bethlehem, a journey of only about a hour and a half on foot, telling them to come back and tell him where the Christ-child was so that he could also worship him. Herod knew of the prophesy that a king was promised to Israel, thus the consequences for any would-be claimant to the throne of David would be severe. When the Magi failed to return he used the old prophecy that the star would appear two years before the birth of the Messiah to justify the slaughter of the innocents, or perhaps about 30 male children in Bethlehem.

In Matthew's Gospel we have one of the major problems in the interpretation of the star. The Magi said it "went before them" and stood over the place where Jesus was born. This we cannot explain. All astronomical objects that last more than a few seconds are so far away that they cannot "stand over" any particular spot on Earth. Is this just poetic licence?

It is perhaps also significant that the Magi were overjoyed to see the star again on their way to Bethlehem. Had they lost it or did it appear twice? If so then it rules out astronomical events that occur only once. Some researchers believe that the wise men saw the star for the first time in their homeland. Having heard that the Messiah would be born in Bethlehem they saw the star for the second time on their way there.

These then are the clues is there anything sources that satisfies them?

It could be a miracle to mark the birth of Christ, but many theologians believe that a miracle is not necessary and that a natural event could be the explanation. It could be fictitious, a literary invention by the author of Matthew to convince his audience that Jesus was the true Messiah. But if this were the case then why is the star of Matthew so mundane when compared with the brilliant star of the Protoevangelium? The tale of Matthew seems ordinary, matter of fact.

Astronomically speaking, many objects and events have been suggested, ranging from exploding stars, meteors, Venus and even Halley's Comet. Venus, the second planet out from the Sun, can be the most brilliant object in the sky after the Sun and the Moon, but it can't be the "star" because it never leaves the dawn or dusk sky. Ancient astrologers would have known all about Venus; it held no great astrological message. Halley's Comet was spotted by the Chinese on 25 August in 12BC and remained visible for 60 nights. No reports of it having been seen in the West have been uncovered. It would have been a spectacular sight in the night sky, but as a contender for the Star of Bethlehem it is four years early. There were a couple of other comets in the more appropriate timeframe of 8-6BC but none of them really fits. Also, comets had little astrological significance at the time.

But there is another vital clue that isn't in the Bible. In 1377 an unknown author wrote in the chronicles of Worcester Priory about a celestial event that happened in AD1285. The planets Jupiter and Saturn had come close together in the sky. Our unknown scholar writes that this had not happened since the Incarnation. Centuries later, Johannes Kepler, last of the great astrologer-astronomers, also believed that a conjunction the term meaning close approach of planets of Jupiter and Saturn was the "Star" of Bethlehem. He believed this because during Christmas 1603 he saw from his observatory near Prague, Jupiter and Saturn coming close together in the sky. It took place in the constellation of Pisces, a constellation with special significance for Israel. He calculated that the last time it had happened was in AD799 and the time before that 7BC. He believed that the coming together of these planets in Pisces happened roughly every 900 years and marked dramatic events for mankind one was the birth of Jesus.

Using today's computers any starmap program can be set to go back to the year 7 and 8BC and show that Jupiter and Saturn came together three times. In late 8BC and early 7BC they were approaching at roughly three degrees a month. On 27 May in 7BC they paused at one degree apart and two months later had separated to three degrees. They came together two more times, being only a degree apart on 6 October and on 1 December, before they moved away from each other and the graceful triple conjunction ended.

To the astrologers of the time the events unfolding in the sky were staggering. Saturn was identified with the God of Israel and Jupiter with the Messiah. They had come together in the constellation of Pisces the water sign. Water falls to Earth and makes it fertile, believed to be the role of Israel among nations. This message in the sky was so powerful that it compelled the Magi to travel.

But perhaps we can stretch the research a little further. If Jesus was born in 7BC and if the conjunction theory is correct then it points to the birth of Jesus in August or September. We have no way of being sure of the exact day but we could take the so-called acronychal rising of Jupiter and Saturn when they were in the sky all night their period of greatest astrological significance. This occurred on the evening of Tuesday 15 September 7BC. Is this the exact birthdate of Jesus?