Star with royal beauty bright
As Christmas comes around we are surrounded by the symbols of the Christian Nativity blended with two thousand years of other traditions. It's the creche and the Christmas tree, the candles and bells, Santa Claus and the three kings, snow and reindeer. But one of the most beautiful - and most interesting to me - is the Star of Bethlehem.
According to the Gospel of Matthew, after Jesus was born in Bethlehem, wise men 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."
Opinions on the nature of the "star" range from those who believe it was an actual star of miraculous appearance to those who dismiss it as a fabrication designed to give authority to the birth story. In between these two are many theories, including those that suggest there was an astronomical reality behind the appearance of the star.
Certainly, it didn't behave like an ordinary star. Except for the Sun, stars are so far away from us that their positions seem to be fixed. They appear to move only as Earth turns and as it orbits the Sun. This isn't enough movement to account for the sightings by the wise men.
However the word "star" was not always as restricted as it is now. Everything heavenly was once considered some kind of star. Meteors were shooting stars, planets were wandering stars and comets were hairy stars. This gives us more to choose from.
We can start by eliminating bright fireballs (large meteors). They're pretty spectacular, but they don't last long.
Then we can eliminate bright planets like Venus or Jupiter. Although people these days might not recognize them, they were common sights to people without electric lights and aircraft. After all, the star would have to be something unusual to get the attention of the wise men and set them off on a long journey.
A better possibility is a nova (short for stella nova, "new star"). These brighten suddenly (within a few days), making them appear to be new objects. They then remain visible for some time before fading again.
A nova isn't actually new. It's caused by the temporary resurrection of a medium-sized star that had run out of nuclear fuel and collapsed. These stars are called white dwarfs and are very dense, so over time their strong gravity can steal enough material from a companion star to set off a thermonuclear explosion. This is a nova.
Even more impressive than a nova is a supernova - the explosive collapse of a massive star at the end of its life. It's as bright as an entire galaxy and can remain visible for quite some time.
Either a nova or a supernova would be a fitting way to announce an important birth, but there are at least two big problems with both of them. Neither object would move around in the sky any more than an ordinary star. In addition, there is no record of either an impressive nova or supernova during the period in which Jesus was probably born.
How about a comet? They do move around and can be quite bright. They're also very dramatic and were thought to herald great events. Halley's Comet was seen seen in 11 BCE, but this is almost certainly several years too early.
Other theories abandon the strictly astronomical for an astrological explanation - long ago both were part of the same discipline. There are numerous suggestions for conjunctions of possible astrological significance. A conjunction is the appearance of at least two astronomical bodies quite close together. These can be verified using planetarium software.
For example, there was a triple conjunction of Jupiter (the king planet) and Saturn in Pisces (astrologically associated with the Jews). The two planets came close together three times in a period of several months in a way that happens only every nine hundred years. Each of the conjunctions could have occurred at a significant point in the story: when the wise men ("astrologers" in some translations) began their journey in early summer, when they met Herod and then as they were on their way to Bethlehem. However this occurred in 7 BCE and some consider this date is a bit too early.
A more spectacular conjunction was that of Jupiter and Venus around 2 BCE, though this is perhaps a few years too late. The two bright planets came so close together that their discs overlapped, making it seem as if they had merged into one. Now that would be something worth seeing! Unfortunately, the next time they appear to be really close in the sky won't be until 2065.
So what was the Star of Bethlehem? No one knows. Did it have an actual astronomical or astrological basis? No one knows. Does any of this diminish its power as a spiritual symbol? Definitely not. Whatever you think and whether you celebrate Christmas or not, this is still a good time to join together in wishing for:
Reference: Nick Stroebel on the Star of Bethlehem, http://www.astronomynotes.com/history/bethlehem-star.html