We human beings love to read about great signs in the sky.
“Do you look for the Star of Bethlehem with the pope’s telescopes?”
Questions like this are all too familiar to those of us of the staff of the Vatican’s astronomical observatory. It is possible to undertake a serious study of the Star of Bethlehem—there was a significant conference on the Star in 2014 at the University of Groningen. But questions about the Star often are about what we human beings want to see in the sky, rather than about what anyone actually did see.
What do we know about the Star of Bethlehem?
The Star of Bethlehem is typically depicted as in the photograph below: an unmistakable sign in the sky; a big, brilliant celestial beacon, guiding the magi to the newborn Christ.
This idea is old. Aurelius Clemens Prudentius lived from 348 to 413. He wrote “Of the Father’s Love Begotten.” He also wrote “Bethlehem, of Noblest Cities.” It includes the following:
Fairer than the sun at morning Was the star that told his birth; To the lands their God announcing, Seen in fleshly form on earth.
These words are a translation, of course. Prudentius actually wrote:
Haec stella, quae solis rotam vincit decore ac lumine, venisse terris nuntiat cum carne terrestri Deum.
The Latin vincere is “to conquer.” Prudentius says the Star “conquers” even the sun—truly a mighty beacon! And so we like to imagine the Star blazing in the night sky:
They looked up and saw a star Shining in the east beyond them far, And to the earth it gave great light, And so it continued both day and night.
But that mighty beacon is not the Star of Bethlehem described by Matthew’s Gospel. Matthew 2 tells us that the magi arrived in Jerusalem, asking about the newborn king. “We saw his star,” they said, “at its rising” (“in the east” is another translation). This news disturbed Herod, who “called the magi secretly and ascertained from them the time of the star’s appearance.”
Herod would not have had to ask when an obvious, bright object appeared in the sky. Everyone would know. It would be the talk of Jerusalem. Those “celestial beacon” images we all know, be they in ancient songs, in beautiful stained-glass windows, or even in tacky plastic illuminated crèche sets, are contrary to what Matthew tells us about the Star. They are about the star we want the magi to have seen in the sky.
Matthew tells us that the Star the magi actually saw was something that Herod and his scholars had completely missed. But it was also something that Herod could in fact see and comprehend. Otherwise, he would have dismissed the magi as crackpots—or, being the sort of person he was, had them killed for stirring up “fake news” about a new king.
Astronomers are very familiar with things in the sky that nobody else sees until we point those things out:
“Oh, there’s Saturn,” we say. “Saturn?” comes the reply, “How do you know that? It looks like just a star. I would have never even noticed it.”
“Look at the difference in color between Arcturus, Vega, and Antares,” we remark. “I never noticed that stars had colors,” we hear back.
What do astronomers tell us about the Star?
So, what was this Star of Bethlehem that only the magi noticed? The Groningen conference, held in response to work by a Rutgers University astronomer, Michael Molnar, discussed that. Molnar, looking carefully at the ideas of astrologers at the time of Christ’s birth, had argued that the Star was a certain arrangement of solar system objects in the sky that would have been significant to those astrologers (see image below). To a trained astrologer, that arrangement corresponded to a royal birth, in Judea. To the average person, it meant nothing. The Star would have passed unnoticed, unless pointed out by someone like one of the magi.