In recent years astronomers have spent countless hours trying to determine what type of celestial disturbance occurred in the night sky at Jesus' birth.
While such observations are certainly fascinating and point to a possible explanation of how the Magi arrived in the area to pay homage to the newborn king, another way to interpret the "star" is to think of it as an "angel of light."
St. John Chrysostom was one of the most vocal theologians who advocated for a "supernatural" star, on account of its ability to guide the Magi to a specific destination. He explains his reasoning in a Homily on the Gospel of Matthew.
[W]hether it was a star by nature or a star in appearance only, we shall easily know the other things also. Whence then will these points be manifest? From the very things that are written. Thus, that this star was not of the common sort, or rather not a star at all, as it seems at least to me, but some invisible power transformed into this appearance, is in the first place evident from its very course. For there is not, there is not any star that moves by this way, but whether it be the sun you mention, or the moon, or all the other stars, we see them going from east to west; but this was wafted from north to south, for so is Palestine situated with respect to Persia.
St. John Chrysostom also points out that the star helped them during the daytime, while they were traveling.
In the second place, one may see this from the time also. For it appears not in the night, but in mid-day, while the sun is shining; and this is not within the power of a star, nay not of the moon; for the moon that so much surpasses all, when the beams of the sun appear, straightway hides herself, and vanishes away. But this by the excess of its own splendor overcame even the beams of the sun, appearing brighter than they, and in so much light shining out more illustriously.
A moving star
One of the most interesting observations of St. JoHn Chrysostom is how the star physically moved and marked out the exact location of the Child Jesus, something a star in the sky could never do.
For it did not, remaining on high, point out the place; it not being possible for them so to ascertain it, but it came down and performed this office. For you know that a spot of so small dimensions, being only as much as a shed would occupy, or rather as much as the body of a little infant would take up, could not possibly be marked out by a star...How then, tell me, did the star point out a spot so confined, just the space of a manger and shed, unless it left that height and came down, and stood over the very head of the young child? And at this the evangelist was hinting when he said,
Lo, the star went before them, till it came and stood over where the young Child was ... Therefore after He has brought them, leading them by the hand, and has set them by the manger; it is no longer by a star, but by an angel that He now discourses unto them.
This is why St. John Chrysostom and others do not believe the star was an actual star, but a supernatural "angel of light," who helped the pagan Magi arrive at the exact location of the Child Jesus.
