The Star of Bethlehem

I wanted to do a special post for the holiday season, so this post is a little different from my normal ones. We’re going to be talking about the Star of Bethlehem, and some theories astronomers have on what this star might have been. Whether you believe in the story of the star (as I do) or consider it a myth (as many do), I hope you’ll find this post interesting.

To start with - what is the Star of Bethlehem? It is the star that foretold the birth of Jesus to the magi. The magi - “wise men” - then followed this star to where Jesus lay.

I had never thought very much about what the star might have been, but this past spring I took an astronomy class. The course was fascinating, and I learned quite a bit, but what interested me the most was a short video I saw discussing the Star of Bethlehem. This was particularly intriguing to me because I attend a non-Christian college. It made me curious, and I’ve since done more research on different theories as to what the star might have been.

Some background information on the wise men is helpful to begin with. Many ancient cultures placed high importance upon reading portents within the stars. Because of this, the magi were more than likely astrologers. They would have assigned great meaning to what they saw happening within the sky.

The most basic theory of the Star of Bethlehem is that it was a nova, or a supernova. A nova is when a white dwarf (think of it as the shell of a dead star) lets off an explosion. Anyone who sees the white dwarf will notice that it appears to be visibly brighter for a period of time afterwards. A supernova is when a star lets off an explosion that destroys the star, and is much brighter than a nova.

The problem with both of these theories is that nova and supernova are highly noticeable - and would have been even more so, before light pollution existed. Ancient astrologers/astronomers from around the world kept records of stars that appeared to grow brighter for a time, and no such record exists in the proper time and place for Jesus’ birth.

The theory that many astronomers today like best involves two concepts that I’ll try to explain. The first is called conjunction (anybody else suddenly get School House Rock stuck in their head?). Conjunction is when two or more objects within the sky pass close together. If you’ve seen the Fifth Element, conjunction is that moment when all of the planets appear to line up perfectly. However, in astronomy objects in conjunction do not have to be directly atop one another. They simply have to be close.

The second concept is called apparent retrograde motion, and this one is a little trickier to explain. All stars have orbits (for this post, we’re also going to consider the planets to be stars, since that was how the astrologers likely saw them.). Apparent retrograde motion occurs when Earth’s orbit takes it past another star. Think of a highway. You’re in your car, and you pass the car in the lane next to you. The car you pass appears to be moving backward relative to your car, even though it’s still moving forward. The same thing is true of the stars. When Earth moves ahead of another star, the star appears to move backward in the sky for a period of time.

Now that you know about conjunction and apparent retrograde motion, let’s talk about my favorite theory of the Star of Bethlehem.

A few years before the birth of Jesus, there was a triple conjunction of Jupiter and Saturn. This multiple conjunction occurred when Jupiter moved into conjunction with Saturn, then past it. Earth then moved ahead of Jupiter due to our smaller orbit, causing apparent retrograde motion that made Jupiter move back into conjunction with Saturn. Jupiter moved past Saturn in the opposite direction...before the apparent retrograde motion ended and Jupiter again moved into conjunction with Saturn!

Remember how I said the magi were likely astrologers that read signs in the sky? Jupiter is named after the Roman god of the same name - who is king over all the other gods. Saturn is the father of Jupiter in the myths, and was king before Jupiter. I’m no astrologer, just a mythology enthusiast, but even I would probably assume that the triple conjunction had something to do with kings!

A year after the triple conjuncture, there was another astronomical event - in case the first one wasn’t enough to pique the interest of the magi. Once again, there were three conjunctions (these ones between Jupiter and Regulus) followed by a conjunction between Jupiter, Regulus, and Venus. Once again, Jupiter is the king of the Roman pantheon. Venus is considered to be the mother goddess of Rome. The Latin word “Regulus” means “prince” or “little king”.

I’m not sure what theory of the Star of Bethlehem is true (there are several others that involve conjunction, apparent retrograde motion, and the constellations of the zodiac that occurred around the time of Jesus’ birth), but I know that they’re very interesting to research and learn about. I hope you enjoyed reading about some of the more prominent theories!

I’ll be back with our last blog post of the year on Monday - a short modern adaptation of the Iliad. Next Friday we’ll start in on Japanese mythology, which is fascinating! I’ll see you then. Hope you guys all had great holidays!