One of the most famous wars between the gods and the Asuras (demons) was the Tarakamaya war. The war was started when Chandra the moon god kidnapped Tara, wife of Brihaspati guru of the gods. (Brihaspati is often just called Guru, and he's the god of the planet Jupiter.). To rescue their guru's wife, the gods fought a great war against Chandra, and the Asuras took Chandra's side because of Sukracharya's personal animus towards Brihaspati. In the end Chandra gave back Tara, but not before she became pregnant with his son, Budha god of the planet Mercury.
In any case, the army of the gods was led by Shiva, who fought on the side of Brihaspati because of his loyaly to Brihaspati's father Angiras, as described in the Vishnu Purana:
In vain Vrihaspati sought to recover his bride; in vain Brahmá commanded, and the holy sages remonstrated; Soma [Chandra] refused to relinquish her. Uśanas [Sukracharya], out of enmity to Vrihaspati, took part with Soma. Rudra [Shiva], who had studied under Angiras, the father of Vrihaspati, befriended his fellow-student. In consequence of Uśanas, their preceptor, joining Soma, Jambha, Kujambha, and all the Daityas, Dánavas, and other foes of the gods, came also to his assistance; whilst Indra and all the gods were the allies of Vrihaspati.
My question is, what is this story of Shiva studying under the sage Angiras?
Now Angiras was one of the mind-born sons of Brahma, so he's certainly old enough. But does anyone know any other scriptures that describe Shiva as a student of Angiras? Are there any other details known about this?
EDIT: I just found out that this chapter of the Srimad Bhagavatam also describes Shiva as a disciple of the sage Angiras:
Because of enmity between Bṛhaspati and Śukra, Śukra took the side of the moon-god and was joined by the demons. But Lord Śiva, because of affection for the son of his spiritual master, joined the side of Bṛhaspati and was accompanied by all the ghosts and hobgoblins.