What does the Bible say about the star?
For something which has become such a solid part of Christmas celebrations, the star doesn't really get much coverage in the gospels; it's more a supporting character. Here's the King James Version of Matthew 2:
1 Now when Jesus was born in Bethlehem of Judaea in the days of Herod the king, behold, there came wise men from the east to Jerusalem,
2 Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him.
3 When Herod the king had heard these things, he was troubled, and all Jerusalem with him.
4 And when he had gathered all the chief priests and scribes of the people together, he demanded of them where Christ should be born.
5 And they said unto him, In Bethlehem of Judaea: for thus it is written by the prophet,
6 And thou Bethlehem, in the land of Juda, art not the least among the princes of Juda: for out of thee shall come a Governor, that shall rule my people Israel.
7 Then Herod, when he had privily called the wise men, enquired of them diligently what time the star appeared.
8 And he sent them to Bethlehem, and said, Go and search diligently for the young child; and when ye have found him, bring me word again, that I may come and worship him also.
9 When they had heard the king, they departed; and, lo, the star, which they saw in the east, went before them, till it came and stood over where the young child was.
10 When they saw the star, they rejoiced with exceeding great joy.
11 And when they were come into the house, they saw the young child with Mary his mother, and fell down, and worshipped him: and when they had opened their treasures, they presented unto him gifts; gold, and frankincense and myrrh.
12 And being warned of God in a dream that they should not return to Herod, they departed into their own country another way.
What did science think about the star?
Herod might have been curious to know about when the star appeared. But he wasn't the last to try and work out what was happening in the sky. Originally - by which we mean in 1603 - Kepler suggested a possible cause:
It was Kepler who noted in 1603 that Jupirer and Saturn were in conjunction; and, as a matter of fact, in the year 7 BC there was a conjunction of Jupiter and Saturn.
About a century ago, the German astronomer C L Ideler discovered that three times in that year these planets were in conjunction - and the last time this happened they were so close that they merged into one.
But, unfortunately, not too long afterwards Charles Pritchard calculated that the planets were never closer than twice the diametere of the full moon.
What does science think about the star now?
There are other theories about the star - although, as EarthSky.org's Larry Sessions explains, most collapse under scrutiny:
First off, we don’t know for sure when Jesus was born. Due to an error by a Church cleric hundreds of years later, the birth of Jesus was thought to be at least 4 years later than it really was. So today we know that the birth was no later than 4 BC, and it could have been a little earlier. And it certainly was not on December 25. The Bible does not say, leaving us few clues. One clue we do have, however, is the reference that shepherds were out in the field “keeping watch over their flock by night” (Luke 2:8), something the scholars say was likely only done in the spring when lambs were born. Thus the birth was likely in the spring, probably between 7 and 4 BC.
Few astronomical records were kept at the time, except by the Chinese and Koreans. They did record what might have been comets in 5 and possibly again in 4 BC. The main problem here is that comets were generally regarded as omens of evil and bad fortune by the Chinese and likely also by the magi-astrologers the New Testament calls “wise men.” Rather than follow such a cometary “star,” they likely would have gone the other way.
Another possibility is that the Christmas Star was a nova or supernova, a previously unseen star that suddenly brightens in a big way. Indeed, one such star was recorded by the Chinese in the spring of 5 BC, and was seen for more than 2 months. However, its position in the constellation Capricornus meant that it likely would not have seemed to “lead” the wise men in the manner implied in the Bible.
Perhaps the star wasn't a guide after all...?
David A Weintrub writes for The Conversation, suggesting that despite what you might have sung in school, the wise men didn't follow the star at all:
If Matthew’s wise men actually undertook a journey to search for a newborn king, the bright star didn’t guide them; it only told them when to set out. And they wouldn’t have found an infant swaddled in a manger. After all, the baby was already eight months old by the time they decoded the astrological message they believed predicted the birth of a future king. The portent began on April 17 of 6 BC (with the heliacal rising of Jupiter that morning, followed, at noon, by its lunar occultation in the constellation Aries) and lasted until December 19 of 6 BC (when Jupiter stopped moving to the west, stood still briefly, and began moving to the east, as compared with the fixed background stars). By the earliest time the men could have arrived in Bethlehem, the baby Jesus would likely have been at least a toddler.
Matthew wrote to convince his readers that Jesus was the prophesied Messiah. Given the astrological clues embedded in his gospel, he must have believed the story of the Star of Bethlehem would be convincing evidence for many in his audience.
Are we minsinterpreting the story?
Perhaps all this confusion is down to how we translate the words. The linguist Richard Coates has considered what might have been lost in translation, from language to language and culture to culture, and posits a new possibility:
The bare bones of a rational account consistent with the Bible story are as follows, then. Astrologers versed in the Persian (and what became the pre-Islamic Arabic) tradition saw a propitious star. Perhaps this was α Aquarii, if any import can be read into the traditional Arabic name westernized as Sadalmelik. It was in a significant geometrical relation with one or more of the unfixed heavenly bodies at its heliacal rising, from which they inferred, in the context of beliefs currently in circulation, that a significant birth had occurred. It is possible to establish with what planets α Aquarii was in conjunction (or some other relation) over a range of years from about 7 BC onwards and it might therefore be possible to narrow down the relevant ones in the light of the astrological characteristics imputed to them by the ancients, leading to a possible narrowing down of the range of possible birth-dates. Using other information not intelligible to us in the light of modern astronomy (but see Keller 1963, Hughes 1976), the astrologers worked out where the event should take place: Palestine. They went there. The relevant star was culminating, some time later, in the south as they travelled south from Jerusalem, with expectations influenced by Jewish lore, specifically by the fact that the prophet Micah (Micah 5:2), and arguably Isaiah (Isaiah 60:3), had foretold such a birth in Bethlehem (Matthew 2:5).
This account is provided as an attempt at explaining how the story could be interpreted without its mythical overlay. It is obvious enough that it has acquired a mythical overlay, intended to point up the exceptional significance of Jesus (cf. conveniently Warner 1976); and the resemblance of parts of it (e.g. the shepherds' visitation; cf. Dieterich 1902, Cumont 1956) to certain aspects of the Mithraic nativity myth is striking and suggests borrowing. But any such myth gains in credibility or acceptability if the events in it can be interpreted as having a familiar kind of factual underpinning, and this is what I have tried to provide without recourse to mistaken identities, abnormal stellar behaviour, astronomical events of extremely rare types, “radical catastrophist cosmology” involving the solar system being turned upside-down (à laVelikovsky 1950), or astronomical near-miss events. Whether the visit of the Magi really took place is beside my point. For what it is worth, I believe that Arnheim's account (1984) is essentially right, despite the occasional minor critical aside on his work here. I have just tried to show that the implied astronomy need not be farfetched, as I think all previous accounts are, and it certainly need not be a fabrication by early writers on the basis of a later cometary visit, as supposed by Jenkins (2004).
Are we trying to search too hard?
The Royal Observatory - who know a thing or two about stars - have a theory that maybe one solution is that there's more than one solution:
Many discussions of possible astronomical explanations for the star of Bethlehem have been made. In the opinion of the writer of this pamphlet none of these explanations is satisfactory but they are summarised below. The 'true' explanation of the star will almost certainly never be ascertained but in my opinion the explanation that the star is a Midrash is the most likely explanation.
A Midrash means a free form of narration in which details are not necessarily historical and the inclusion of legendary elements is allowed. The tradition, in fact, expects such additions to be made to accentuate the religious meaning of the factual account. This does not mean that Matthew invented the story of the star but that he knew of traditions concerning Christ's birth and incorporated them into his account so as to convey to the reader the miraculous way in which Christ was born. His aim would have been to convey the good news of salvation i.e. the 'gospel'.
None of these possible explanations appears to have overwhelming evidence to indicate that it should be preferred to any of the others. It is difficult to see how any of them fulfils St. Matthew's idea that this was a miraculous event. There appears to be little to distinguish between the three classical explanations that the star was:
has a scientific explanation
a supernatural event
The suggestion, given above that it was a Midrash seems to the author as likely an explanation as any.