Was Nestorius Ever Excommunicated by the Catholic Church?

Question

From what I gather, Nestorius rejected Mary as the Theotokos (which means "God-bearer") and proposed instead that she merely be called, the Christotokos; or rather, "Christ-bearer" because since Mary was a human being---God could never be born of a creature. Hence, (with some details omitted) this would necessarily imply that there were two distinct persons in the Incarnate Christ---one human and one divine accidentally united in one body (in violation of the dogma of homoousios defined at the First Ecumenical Council of Nicea in 325 that God the Father and God the Son are of the same substance).

It is not clear whether or not Nestorius explicitly taught that there exists two natures in Christ, but his doctrine necessarily leads to that conclusion.

Hence, with this heresy, it could neither be said that God was born, nor that He was crucified, nor that He died---and therefore, neither that He rose from the dead. And so, as the Holy Spirit tells us in 1 Cor. 15:17: if Christ be not risen again, your faith is vain, for you are yet in your sins.

The First Council of Ephesus in 431 condemned Nestorius' teachings as heretical and deposed him from his See (Nestorius was the patriarch of Constantinople at the time.)

Was Nestorius ever formally excommunicated by the Catholic Church?

I have now noticed that this question seems to be somewhat connected with the one posed here: Proof that Cyril of Alexandria is a Saint in the Roman Catholic Church?, for Catholic Encyclopedia in the entry for Pope St. Celestine I says (regarding St. Cyril of Alexandria):

Cyril having found Nestorius openly professing his heresy sent a full account to Celestine, who in a Roman synod (430), having solemnly condemned the errors of Nestorius, now ordered Cyril in his name to proceed against Nestorius, who was to be excommunicated and deposed unless within ten days he should have made in writing a solemn retractation of his errors. In letters written the same day to Nestorius, to the clergy and people of Constantinople, and to John of Antioch, Juvenal of Jerusalem, Rufus of Thessalonica, and Flavian of Philippi, Celestine announces the sentence passed upon Nestorius and the commission given to Cyril to execute it. At the same time he restored all who had been excommunicated or deprived by Nestorius. Cyril forwarded the papal sentence and his own anathema to Nestorius.

Nevertheless, it is not clear to me whether or not Nestorius had been officially excommunicated.

Answer 1

Evidently, in 431, Pope Celestine excommunicated Nestorius at the 2nd council of Ephesus.

So, a pope did excommunicate Nestorius. And it was ratified in an official synod. Those two details would make me conclude that the excommunication had staying power later on. However, to my knowledge, later popes have not made a condemnation of Nestorius ex cathedra. So this excommunication is subject to change.

Answer 2

Was Nestorius Ever Excommunicated by the Catholic Church?

It would seem that Nestorius, despite many anathematizes, was never officially excommunicated by the Church. Numerous bishops pronounced such against him. The pope even condemned his doctrines, but never officially excommunicated (anathema) him.

Cyril had to explain that he was not summarizing or defining the faith about the Incarnation, but simply putting together the principal errors of Nestorius in the heretic's own words. In his books against Nestorius he had occasionally misrepresented him, but in the twelve anathematisms he gave a perfectly faithful picture of Nestorius's view, for in fact Nestorius did not disown the propositions, nor did Andrew of Samosata or Theodoret refuse to patronize any of them. The anathematisms were certainly in a general way approved by the Council of Ephesus, but they have never been formally adopted by the Church. - Nestorius and Nestorianism

The Council of Ephesus was a council of bishops convened in Ephesus in AD 431 by the Emperor Theodosius II. This third ecumenical council, an effort to attain consensus in the church through an assembly representing all of Christendom, confirmed the original Nicene Creed, and condemned the teachings of Nestorius, Patriarch of Constantinople, who held that the Virgin Mary may be called the Christotokos, "Christ-bearer" but not the Theotokos, "God-bearer". It met in June and July 431 at the Church of Mary in Ephesus in Anatolia.

Pope Celestine had died on July 26 and the Council of Ephesus ended on July 31 and thus he could not have confirmed the decisions of the council.

Nowadays only the Pope can excommunicate a bishop outside automatic excommunications as stated in Canon Law. Back then I guess the rules were not so clear.