Was the Star of Bethlehem a real astronomical event?

There have been quite a lot of people who've looked into this sort of thing to see whether it was actually a real event. In fact, my lecturers when I was back at university wrote a paper on that exact same thing. He looked at the theory that if you get Jupiter, Saturn, Mars and as many planets as possible in the same spot in the sky, can you get a star bright enough to look like the Star of Bethlehem? He found that that probably wasn't the case, as it wouldn't have been bright enough. However, there are some other possibilities. These include comets, asteroids and possibly supernovae as well. When stars explode, they can give out as much light as an entire galaxy, but they don't last for a very long time. This could be an explanation.