Now when Jesus was born in Bethlehem of Judea in the days of Herod the king, behold, there came wise men from the east to Jerusalem, 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. …
Then Herod, when he had privily called the wise men, inquired of them diligently what time the star appeared.
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.
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.
When they saw the star, they rejoiced with exceeding great joy.
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.
Matthew 2: 1-2, 7-11; King James Bible
You can't have the Christmas story without the star of Bethlehem … even though it may not have been a star at all.
The star is featured prominently in the biblical account of the birth of Jesus. Without it, the Magi would not have known where to go to find the new king. It was a guidepost for them, a long-lasting signal in the heavens.
But how did they know what the star foretold? What was the star? Was it a miracle, a one-time celestial event that has never been repeated, or something explainable by science?
No one knows for certain.
Meteors, novae, supernovae and comets often come up as possible explanations, said Wayne Harris-Wyrick, director and staff astronomer of the planetarium at Science Museum Oklahoma. None of them really match the description, though.
Meteors move quickly, producing a transient streak of light that's there one moment and gone the next, he said. That rapidity makes a meteor an unlikely candidate for the Christmas star. The wise men followed the star, suggesting that it hung in the heavens for the duration of their journey. If it had been a meteor, they would've missed it if they'd blinked.
A nova involves two stars that are close to each other. The smaller one, a white dwarf, draws in hydrogen from its companion star. After awhile, the white dwarf erupts in nuclear fusion, releasing energy and light for a limited period of time. A nova would grow in brightness in the night sky.
So would a supernova, but it would produce even more light.
“A supernova is a star that literally blows itself apart,” said Harris-Wyrick, 60, who is showing a “Star of Wonder” program at the planetarium throughout the holiday season. “It could happen by the same mechanism as a binary star, but it could also happen in other ways. A nova is a temporary brightening; a supernova blows apart.”
The duration of a nova or supernova would work with the biblical scenario. Both would be noticeable to those who watch the stars. Both would be visible for plenty of time.
No such explosions in the sky are known to have been observed around the time of Christ's birth, Harris-Wyrick said. Chinese astronomers observed the first recorded supernova (RCW 86) in 185 A.D., many decades too late to fit the timing of the Christmas star.
A comet makes more sense, especially since comets can be seen as lines in the sky, almost like arrows pointing to specific locations. Astronomers have tried to identify a comet that would fit the time period, but without success.
“The best match is an apparition of Halley's comet,” he said, “but that was 7 years too early.”
When was Jesus born?
How do we know what was too early and what was too late? Do we know exactly when Christ was born?
The short answer is no.
The long answer is … sort of.
Jesus was born during the reign of King Herod, who died in the winter of 4 B.C., Harris-Wyrick said. Christ's birth had to predate Herod's death.
Mary and Joseph went to Bethlehem for a census, he said. They would be counted and taxed by the Romans. Only three censuses occurred under the rule of emperor Caesar Augustus; these took place in 27 B.C., 7 B.C. and 14 A.D. The first date is much too early; the last is much too late.
After Jesus' birth, an angel told Joseph to take his family into Egypt to hide from Herod, who was so desperate to eliminate Jesus that he ordered the deaths of children ages 2 and under. Jesus remained in Egypt until after Herod's death.
All those parameters (and a few more) suggest that Jesus was born sometime between March and May of 6 B.C., Harris-Wyrick said.
As it turns out, something was happening in the skies around then. It didn't involve stars, though; it was all about the planets.
Who were the wise men?
The wise men likely were Zoroastrian priests and astrologers from Persia, who watched the skies carefully for omens and portents.
Much of the time, the “Star of Wonder” presentation notes, they focused on five “wandering stars.” These stars weren't fixed in space the way countless others were. They moved around, sometimes in surprising ways.
They were, of course, five of the planets in our solar system. And some of them would've given the Zoroastrians quite a show in the months leading up to Christ's birth.
Like Earth, the other planets orbit the sun. From time to time, one planet seems to catch up with another; although they're separated by a vast gulf of space, it looks as if they're very close together, almost in danger of smashing into each other. This is called a conjunction.
During the relevant time period, Jupiter and Saturn entered into an interesting conjunction. Jupiter, which the Zoroastrians considered the chief god in space, appeared to chase Saturn across the sky — drawing near, overtaking Saturn … and then going backward.
“Because Earth is also a planet moving around the sun, as Jupiter is moving and Earth is moving faster, it can catch up and make it look like Jupiter is going backward,” Harris-Wyrick said. “It's called retrograde motion. … It's not real. It's an illusion. Jupiter passed Saturn right at a point where Earth was about to pass both in space.”
From the ground, watchers would have seen Jupiter pass Saturn (which was regarded as the protector god of the Hebrews) going one direction, then reverse to pass Saturn going a different direction, then revert to its original direction and pass Saturn a third time.
“A few months later, the baby was born in Palestine, in Bethlehem,” Harris-Wyrick said. “Here's the chief of the Gods (Jupiter) visiting the protector God (Saturn) three times. The Zoroastrians knew this was the house of the Hebrews. If you believe everything in the sky is telling you something, how are you going to interpret that? A very powerful king was being born on Earth.”
So there's your explanation: The Christmas star was a conjunction of two planets. Three, really, since the Earth's position relative to the other two made Jupiter appear to move forward and back.
But it's not the only explanation.
In her 2012 book, “Unraveling the Christmas Star Mystery,” Irene Baron argues that astronomers like Harris-Wyrick are only half-right.
Baron, a former high school and college science teacher, used NASA astronomy programs to see what would've been visible in the skies over a 15-year period ranging from 7 B.C. to 7 A.D. (Technically that's a 14-year period, since there is no year Zero, but Baron included a zero in her calculations.)
“In researching ancient astronomers,” Baron said in a phone interview from her home in Ohio, “I learned they did not make their observations at night but at dawn and in the pre-dawn hours. Most modern astronomers were looking at the night sky. … I set my search for 6 a.m. Bethlehem time. I looked and looked and looked. I finally did find the Christmas star.”
Which was Saturn.
Ancient astronomers would have watched as Saturn wound through a series of alignments and eclipses, she said. Then they would have watched the wandering star climb higher in the sky throughout November of 4 A.D. By early December, Baron said, the planet would have seemed to be over Bethlehem at daybreak.
“The astronomers, with their mathematics and planning, knew all these celestial events would happen and knew when and where they would all end,” she wrote. “By going to the location below the Saturn god, they would find the birth place of the new Earthborn God, just outside of Bethlehem. Jesus Christ must have therefore been born in early December” of 4 A.D.
Baron's theory isn't the only alternative, either. Some suggest the star was a long-term comet modern man doesn't know about. Others say it was the conjunction of a planet and a bright star, a one-of-a-kind celestial event or even an alien spaceship.
Many believe it was a miracle.
“The Jupiter and Saturn conjunction may be the answer,” Harris-Wyrick said. “But in the end, we're just speculating. We could be off a little bit in all these things. Ultimately, it could be nothing scientific at all. …
“What matters is what it signifies.”