A depiction of the Star of Bethlehem. Image credit: Garrett W. / CC BY
Right around Christmas time, a lot of people come up to astronomers and ask what the Star of Bethlehem could have been. This “star”, also called the Christmas Star, is said to have appeared in the sky in time to announce the birth of Jesus Christ to the Three Wise Men, and would have lead them to Bethlehem, to honour the newborn. Modern astronomers are now trying to figure out what astronomical event might have appeared in the skies all those years ago as the Star of Bethlehem. In order to do that, it is first necessary to try and pin down the actual birthdate of Jesus. Historical clues recovered throughout many different sources seem to indicate that he may have actually been born around the year 5 B.C. Furthermore, some believe the Star of Bethlehem did not appear right when he was born, but perhaps a year or even more later. This wide range of years have left us with quite a few theories as to the real identity of the Christmas Star:
1) A series of two or more planets in near alignment in the sky may have been seen as a single very bright star. Using known planetary orbits, we are finding it difficult to find such an alignment to have occurred at the right time, unfortunately.
2) Some Chinese astronomers recorded a new star born from a supernova that was highly visible for 70 days in the constellation of Capricorn around 5 B.C. However, the religious scripts state that the Christmas Star moved from East to South over the course of many months, which cannot be so easily conciliated with a supernova progenitor.
3) A comet might have been the culprit, but they were typically seen as bad omens. Furthermore, we cannot find any other mention of such a noteworthy object in the literature.
4) Jupiter, a planet that can indeed be very bright in the sky, may have seemed near immobile due to it being at the end of one of its retrograde loops.
The verdict is still out as to what the Star of Bethlehem truly was. Despite all our technological advances, it may be difficult to backtrack to a definitive answer so many years in the past.
Merry Christmas!