The world's largest alchemy research center was in Egypt. During his years at Hogwarts, Albus Dumbledore had attended an international alchemy conference there and received a gold medal for pioneering contributions.
Over a meal once, he had mentioned to Pomona the Horus alchemy researched there.
From the Middle Ages until now, mainstream European alchemists had considered themselves disciples of Hermes. Few people still studied the Egyptian alchemy from which it had all originated.
Pomona did not understand Horus alchemy very well, and Albus had not gone into detail. He had only vaguely mentioned sons and mothers.
Isis was Horus's mother. Like Ancient Greek temples, Egyptian temples had priestesses. Egyptians observed Sirius in order to observe the Nile River, while the priestesses of the goddess Isis had to observe Alpha Boötis. They underwent training to form a resonance with Alpha Boötis, and that process was called meditation.
Alpha Boötis was also one of the fifteen magical stars. It was the brightest star in the northern night sky, while Sirius was in the southern sky. Its name came from the Greek words "Arktos" and "Arcturus," meaning "Guardian of the Great Bear."
Zeus, king of the gods, secretly fell in love with Callisto, an attendant of Artemis, the goddess of the moon and the hunt. He truly did love spreading his affections around. Later, Callisto gave birth to a son, Arcas. When Hera, queen of the gods, learned of it, she transformed Callisto into a great she-bear in a fit of rage. Hera could not do anything to her husband, but she was quite adept at dealing with a mere attendant.
Later, the young Arcas grew up. One day, while hunting in a dense forest, he was spotted by his mother, Callisto. Forgetting that she was now a bear, Callisto stretched out her