"Angelology": Study of Angels

October 2nd is the "Feast of the Guardian Angels" (Catholic encyclopedia): https://www.newadvent.org/cathen/07050a.htm

Hence today I was thinking of angels; "Angels" entry: https://www.newadvent.org/cathen/01476d.htm

"Guardian Angel" entry: https://www.newadvent.org/cathen/07049c.htm

Wiki entry on "Angel": https://infogalactic.com/info/Angelology

Wiki entry on "Feast of Guardian Angels": https://infogalactic.com/info/Memorial_of_the_Holy_Guardian_Angels

That every individual soul has a guardian angel has never been defined by the Church, and is, consequently, not an article of faith; but it is the "mind of the Church", as St. Jerome expressed it: "how great the dignity of the soul, since each one has from his birth an angel commissioned to guard it." (Comm. in Matt., xviii, lib. II).

The angels are thought to exist in a hierarchy of 9 kinds:

In the first hierarchy [Aquinas] places the Seraphim, Cherubim, and Thrones; in the second, the Dominations, Virtues, and Powers; in the third, the Principalities, Archangels, and Angels.

Any thoughts on angels today?