While the best way to describe the phenomenon that lead the Magi (Wise Men) to the place where the Christ Child was is to refer to it as a star, I doubt that it was a literal star that was seen.
Matthew 2:7: Then Herod, when he had privily called the wise men, enquired of them diligently what time the star appeared.
First only the Magi saw the star if it were a literal star it would have been seen by many others and they too would have followed this star. Herod and those in his court did not see the star so he inquired of the Magi what time the star appeared.
Matthew 2:9 When they had heard the king, they departed; and, lo, the star, which they saw in the east, went before them, till it came and stood over where the young child was.
The star appears to have a mind of its own; it reappears and once again leads the Magi when they left Herod’s palace and continued their journey in search of the Child (It was obviously not visible while the Magi spoke the Herod or he would have seen it and not inquired concerning it). But the most amazing trait of this star is that it stood over where the young child was. No star has ever behaved in this manner.
So if it was not a literal star what was it?
Genesis 1:1-4 In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. And God said, Let there be light: and there was light. And God saw the light, that it was good: and God divided the light from the darkness.
In the creation story we learn that light appeared on the first day of creation but this was not the sun (A star) since the sun was not created until day four of creation.
Genesis 1:14-15 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
The light that appeared on day one of creation was that Glory of the Almighty God. This is the same light that will illuminate the New Jerusalem at the end when God sets up His eternal kingdom.
Revelation 21:23 And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof.
So the star that led the Magi was the same that illuminated the earth on day one of creation and the same that will illuminate the city that shall descend from heaven like a bride adorned for her husband. The star that led the wise men was the Glory of God.