Often around Christmastime, some article apprears speculating about that star (like this one from 2006 about it being a nova, Giotto, above, pictured it as a comet). It always reminds me of a wonderful astronomy course I took in Highschool at the local college. The professor's last lecture was on the Nativity Star.
He had written a long article about the Star of Bethlehem, wherein he described several different cosmic events that *could* have been the "star" leading to the Christ-child in or around the year 0. There were several possible planetary alignments, like the one described in the article above; there was the possible passing of a comet; there were speculations about the birth or fading of an important star in the middle-east cosmology. And everyone he described seems utterly convincing and reasonable.
But, if he, a knowledgeable but not important astronomer could discover several "possible" stars, why would any of those events be uncommon enough to lure the Wise men. To impress the Wise men, astronomers and scientists themselves, it would have had to have been something truly extraordinary, and perhaps unexplainable, to bring them to travel so far, and want to do homage to the newborn king. The alignment of Venus and Jupiter is not uncommon. But the star of Bethlehem truly was.
So, to quote my favorite novel:
"But, my dear Sebastian, you can't seriously believe it all."(Ht: The Courtier, and American Papist)
"I mean about Christmas and the star and the three kings and the ox and the ass."
"Oh yes, I believe that. It's a lovely idea."
"But you can't believe things because they're a lovely idea."
"But I do. That's how I believe."