What's Up in the Sky - Astronomy and the Mystery of the Star of Bethlehem

Fred Barrett | Dec 20, 2012

To try and figure out what celestial event might have been the Star of Bethlehem 2000 years ago, we must have a reasonably accurate idea of when Jesus Christ was born. Theological historians place the birth of Jesus in September or October in 3 or 2 BC. They researched several historical facts derived from biblical accounts in Matthew and Luke to arrive at that date. These facts included the date of the census taken at that time, who was ruling Judea and Syria and the death of Herod in 1 BC.

First, it must be noted that in ancient times the word ‘star’ could be interpreted several ways. It could be any bright object that traveled across the sky. We can discount a meteor shower or Supernova as the Star of Bethlehem. Accounts require that the bright object appear in the eastern sky, cross the starry background and move before the Magi to Judea. Meteors travel quickly across the sky and a shower lasts only a short time. No Supernova was reported during the period we are investigating. We can also discount comets because they were considered to be signs of evil and bad omens. That leaves us with planets or groupings of planets to match the biblical description and there are a series of conjunctions that roughly fit our time period. A conjunction is when 2 or more planets and/or stars come close to each other.

Matthew relates that the star appeared in the rays of the rising Sun. On August 1st, 3 BC, Jupiter rose up in the light of dawn. At 5 AM on August 13th, Jupiter and Venus were very close together. A few days later on the 18th Venus and Mercury appeared at dawn in a conjunction. On September 14th Jupiter was in conjunction with the very bright star Regulus. Jupiter and Venus, the 2 brightest planets in the sky, were so close, they appeared to fuse together. A grand conjunction of planets occurred on August 27th when Jupiter, Mars, Mercury and Venus were a tight bundle at sunrise. By mid-October the Magi saw Jupiter above Bethlehem. Jupiter had reached its farthest point west and stood still against the stars high in the sky above Bethlehem.

Many will argue for other astronomical explanations for the Star of Bethlehem. For me, the above series of conjunctions best explains the brightness in the sky that guided the Magi.

Though there are religious barriers on Earth, the symbol of the Star of Bethlehem shining with all the stars in the heavens above symbolizes hope and joy and friendship during Christmas, Hanukah, and Ramadan and with all who hold this holiday season dear.

A very Merry Christmas and a Happy New Year to all!

If you have questions or suggestions, Fred Barrett may be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it.

The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..