Description: A slowly moving, and at one point stationary, bright object in the night sky, visible from kingdoms in the East (most likely Persia or Arabia)
Significance: It leads the Magi to find Jesus, first telling them something significant is happening, and then stopping directly over his birthplace.
First Sighting: It is only referenced explicitly in five verses of one chapter of the gospel. In Matthew Chapter 2 it says:
"After Jesus was born in Bethlehem in Judea, during the time of King Herod, Magi from the east came to Jerusalem and asked, "Where is the one who has been born king of the Jews? We saw his star when it rose and have come to worship him.'" (Verses 1-2)
"Then Herod called the Magi secretly and found out from them the exact time the star had appeared." (Verse 7)
"After they had heard the king, they went on their way, and the star they had seen when it rose went ahead of them until it stopped over the place where the child was. When they saw the star, they were overjoyed." (Verses 9-10)
There are some disputed earlier reports that it is prophesised about in the book of Numbers.
"I see him, but not now;
I behold him, but not near.
A star will come out of Jacob;
a sceptre will rise out of Israel.
He will crush the foreheads of Moab,
the skulls of all the people of Sheth."
(Numbers Chapter 24, Verse 17)
Because there was no Kingdom of Moab at the time of Jesus's birth, leading modern scholars sometimes argue that this passage must have been about the immediate future of when it was written, and not a long term prophecy, (Numbers was written between 1450-1410 BC).
But many writers in the first century AD thought this was a prophecy relating to their time. Roman historian Josephus believed that it referred to Roman Emperor Vespasian.
Origen, one of the earliest Christian theologians, definitely thought this was a prophecy about Jesus. He wrote "with respect to the appearance of a star at the birth of Jesus there is a prophecy of Balaam recorded by Moses to this effect: There shall arise a star out of Jacob, and a man shall rise up out of Israel."
Explanation: While it could of course be a completely miraculous object, the most commonly believed purely material theory is that the star was a confluence of several stellar objects. In coming together, they would have produced a single bright point of light, making an object of special note in astronomers' records, drawing the attention of people like the Wise Men.
In the 2006 film "The Nativity Story", the Wise Men are shown as discussing the confluence of Venus, Jupiter, and the star Regulus. The significant point is that Jupiter was known by the Romans as the "sky-father" while Venus had great significance as a maternal figure. Regulus, as its similarity to the word Regal suggests, is a star of Royal form. The Babylonians knew it as Sharu, meaning King, and the Greeks were even closer, naming it Basiliskos Aster or Little King Star. Mother, Father, and a little King.
This was further supported in 2011 when Australian astronomer Dave Reneke used a computer simulation to depict where the stars would have been in the sky approximately 2,000 years previously. "We have software that can recreate exactly the night sky as it was at any point in the last several thousand years," said Mr Reneke in The Telegraph.
According to this simulation, Venus and Jupiter would have appeared very close together in the Constellation of Leo, where Regulus is one of the more significant stars. It is an interesting aside that Leo is the constellation the star is found in, when Jesus is so often described as the "Lion of Judah".
Other theories have suggested a comet or a nova (an exploding star) but none of these have substantial corroboration. Both of these events would have been recorded by ancient Chinese astronomers who were operating and recording events at the time. A confluence of Regulus, Jupiter and Venus seems to be the most likely explanation.