It seems to me that the question is based on speculation. What is “Magian Astrology” supposed to be in the context of the Bible? The Google search engine returns no hits for this term. For the alternative term “Magi astrology”, Goggle returns a Wikipedia page about system of astrology introduced to the public by the Magi Society, its originator, through its three books published from 1995-1999.
As far as I am aware there is no explanation in the Gospels as to how the wise men of the East came to consider an astronomical event (the star in the East) as a sign of the birth of the king of the Jews in Bethlehem as prophesied by the prophet Micheas (Matt. 2:6, Mich 5:2). The only reference to the wise men is in the Gospel of St Matthew, Chapter 2:
[Mt 2:1]When Jesus therefore was born in Bethlehem of Juda, in the
days of king Herod, behold, there came wise men from the East to
Jerusalem,
[Mt 2:2]Saying, Where is he that is born king of the Jews? For we have
seen his star in the east, and are come to adore him. (Douay-Rheims
Bible/Challoner Revisions)
The Wikipedia article
http://en.wikipedia.org/wiki/Biblical_Magi
states that the English term “wise men” as used in the KJV and DRB is a translation from the Greek word “Magoi”, itself derived from the old Persian term “Magus”, describing a member of the priestly caste of Zoroastrianism. This caste was known for its knowledge of astrology, which at that time was the study of anything to do with the stars, and therefore included astronomy. It is likely that anybody who at that time engaged in what we would today regard as scientific investigation would have acquired whatever knowledge of astronomy existed at the time and been considered a wise man or magus. The Latin word “Magus” derived from the Greek later came to mean a wizard, sorcerer, or magician - hence the English word “magic”. Thus the meaning of the word "Magus" evolved over time. The fact that the Greek word "Magoi" is derived from the Persian word "Magus" does not necessarily mean that it had exactly the same meaning. It could have meant just “wise men” or “wise kings” as interpreted by the English translators of the Bible.
It seems likely that the wise men would have acted upon one or more prophesies in the Scriptures rather than on some astrological prediction in the modern sense of the term. One possibility is that they may have taken into consideration the so-called “Star prophesy”:
[Numb. 24:17] I shall see him, but not now: I shall behold him, but
not near. A STAR SHALL RISE out of Jacob and a sceptre shall spring up
from Israel: and shall strike the chiefs of Moab, and shall waste all
the children of Seth.
In my opinion the Catholic Church and other Christian denominations should reject all forms of magic, divination, and witchcraft, because such “powers” conflict with the concept that only the one and only God, or prophets or saints filled with the Holy Spirit, could possibly possess such powers. In other words, forms of divination fall into the realm of activities inspired by the enemies of God.
More specifically, Catholics (and Christians in general) should reject astrology because sorcery, witchcraft and astrology are condemned in the Bible multiple times; as, for example, in the following Bible passages:
A
Isaiah 47:12-14
12 Stand now with thy enchanters, and with the multitude of thy
sorceries, in which thou hast laboured from thy youth, if so be it may
profit thee any thing, or if thou mayst become stronger.
13 Thou hast failed in the multitude or thy counsels: let now the
astrologers stand and save thee, they that gazed at the stars, and
counted the months, that from them they might tell the things that
shall come to thee.
14 Behold they are as stubble, fire hath burnt them, they shall not
deliver themselves from the power of the flames: there are no coals
wherewith they may be warmed, nor fire, that they may sit thereat.
B
Malachias 3:5
5 And I will come to you in judgment, and will be a speedy witness
against sorcerers, and adulterers, and false swearers, and them that
oppress the hireling in his wages, the widows, and the fatherless: and
oppress the stranger, and have not feared me, saith the Lord of hosts.
C
Galatians 5:19-21 19 Now the works of the flesh are manifest, which
are fornication, uncleanness, immodesty, luxury, 20 Idolatry,
witchcrafts, enmities, contentions, emulations, wraths, quarrels,
dissensions, sects, 21 Envies, murders, drunkenness, revellings, and
such like. Of the which I foretell you, as I have foretold to you,
that they who do such things shall not obtain the kingdom of God.
D
Apocalypse 9.21 Neither did they penance from their murders, nor from
their sorceries, nor from their fornication, nor from their thefts.