What is the Authoritative Catholic explanation of why the Magi get a pass, yet Catholics are to reject astrology? What is the authoritative Catholic explanation of why the Magi get a pass, yet Catholics are required to reject astrology?

Catechism of the Catholic Church | Divination and magic, 2116 has: 


  All forms of divination are to be rejected: recourse to Satan or demons, conjuring up the dead or other practices falsely supposed to "unveil" the future [Cf. Deut 18:10; Jer 29:8]. Consulting horoscopes, astrology, palm reading, interpretation of omens and lots, the phenomena of clairvoyance, and recourse to mediums all conceal a desire for power over time, history, and, in the last analysis, other human beings, as well as a wish to conciliate hidden powers. They contradict the honor, respect, and loving fear that we owe to God alone.


The Magi utilizing their Magian astrology, were led Christ.

It appears that the stars have a knowledge, a science.

What made the Magian astrology acceptable, and would that type of Astrology be permissible to Catholics?



Please see this answer also: What types of signs are given by the “lights in the expanse of the heavens”?
The Magi used their Magian astrology to recognize what was happening now. But astrologers use astrology to find out what is going to happen in the future. Note that Magi's saw Jesus in a house (Mat 2:11) not in the birth place of Christ.

//It appears that the stars have a knowledge.//

Stars do not have knowledge on their own. But God uses nature to instruct gentiles to recognize the birth of the Messiah.

//Why would the Catholic Church require Catholics to reject astrology//

The answer to this is in CCC 2115: 


  God can reveal the future to his prophets or to other saints. Still, a sound Christian attitude consists in putting oneself confidently into the hands of Providence for whatever concerns the future, and giving up all unhealthy curiosity about it.


That is, future is in God's Hand and humans have no business in there.