Knowledge of astrology
No one is sure who the Magi or wise men were. But most believe they would have had knowledge of astrology, which was widely practiced but not by the Jews, he said.

Next, Molnar had to figure out what the Magi were watching for, keeping in mind that in those days "star" referred to anything in the heavens. Jupiter was considered to be the star of kings, Molnar said.

Molnar used a computer program to recreate the positions of the stars and planets that would have been visible between 8 B.C. and 4 B.C. What he found was that in 6 B.C. Jupiter did some unusual things in the constellation Aries.

On April 17 of 6 B.C., the moon would have blocked the view of Jupiter. Saturn and the sun would have appeared at the edge of Aries.

This eclipse of Jupiter by the moon and the positions of Saturn and the sun with relation to Aries would have held significance for astrologers, Molnar said.

"It was considered the magical formula for the birth of not just a great king but a divine king," Molnar said.

Also Molnar thinks "in the east" could be more accurately translated as "at its rising," meaning a morning star.

On April 17, Jupiter would have been visible in the morning sky.

Molnar thinks it was all these factors that made the Magi set out for Jerusalem.

And the star would have in a sense stayed with them. About Aug. 23, Jupiter would go into retrograde motion, meaning it would appear to move from east to west instead of its normal west to east.

Then around Dec. 19, Jupiter would have appeared stationary.

When the Magi arrived at King Herod's court, he and his advisers were surprised by their talk of a star.

"Those people who practiced astrology recognized the star," Molnar said. "The Jewish people and King Herod didn't see it. He would have seen a comet or a nova."

Other interpretations
Molnar is confident in his theory, but there are other interpretations.

"There is truth behind this story," Molnar said. "Yes, granted it is not what some people would want it to be - a brilliant star or comet .

Others, such as Meadowood Baptist's Mattox, think the star was a miracle sent by God to tell of the birth of Jesus.

"To me, it was a star that appeared at that time as a divine sign from God," said the Rev. Francis Schmidt of St. Martin's Catholic Church in Cross Plains. "It appeared by the power of God, and once it's job was finished it was gone."

Others think Matthew included the information about the star to reach out to non-Jews who would not have believed a Jewish prophecy about a savior but would have believed in astrology.

Matthew begins his Gospel with a list of Jesus' genealogy to prove to Jews that Jesus is the savior, said the Rev. Phil Kenas of Sun Prairie's United Methodist Church.

"The way that he verifies it for the general public is there is attestation and it's a heavenly attestation," Kenas said. "It's a way of broadening the appeal."

Still others say the star was a literary device added to make the birth of Christ even more important.

"It makes more sense, especially given a lot of contradictions or at least gaps here - especially that thing about the star leading them to Bethlehem," UW Space Place's Lattis said. "I don't know what kind of celestial event would do that."

Many pastors, however, said it doesn't really matter what the star was. It just comes down to faith.