Introduction
Dhruva is one of the eight Vasus, the elemental gods who attend Indra. His name means "fixed", "firm" or "steadfast", and he represents the pole star, the fixed point around which the sky seems to turn. He is not the same person as the child devotee Dhruva of the Bhagavata Purana, who is said to have become the Pole Star through his devotion to Vishnu.
The Vasus are a group of eight elemental gods, attendants of Indra. The word vasu means "bright" or "dwelling", and also "wealth". In the Vedic tradition, the eight Vasus are counted in different ways. The Brihadaranyaka Upanishad identifies them as Fire, Earth, Wind, Atmosphere, Sun, Sky, Moon and the Stars. In the Puranas and the Mahabharata, the eight are named individually. The Vishnu Purana lists them as Apa, Dhruva, Soma, Dhara, Anila, Anala, Pratyusha and Prabhasa, and the Mahabharata gives nearly the same names. In the Bhagavad Gita, Krishna says that among the Vasus he is Pavaka, the fire.
In the Puranic lists
In the Vishnu Purana, Dhruva is one of the eight Vasus, and his son is Kala, "Time". The name appears in the Mahabharata list of the Vasus as well.
The two Dhruvas
The Puranic Dhruva is a boy prince, the son of King Uttanapada, who was rejected by his stepmother and was told he could not sit on his father's lap. He went to the forest and performed austerities for Vishnu, who granted him a place as the Pole Star (Dhruva Tara), a fixed point in the sky, and the right to rule. The name is the same because both represent constancy. The two figures are separate in the tradition.
The story of the Vasus
In the Mahabharata, the eight Vasus were once travelling with their wives when the wife of one of them, Dyaus (Prabhasa), saw the wish-granting cow Nandini in the hermitage of the sage Vasishtha. She wanted it for a friend, and Prabhasa, with his brothers, stole the cow. Vasishtha discovered the theft and cursed the Vasus to be born as humans. When the Vasus begged for mercy, he said that seven of them would be freed as soon as they were born, but Prabhasa, who had led the theft, would live a long life on earth.
The Vasus asked the river goddess Ganga to be their mother on earth. She married King Shantanu and drowned the first seven sons at birth to free them. The eighth was saved by his father, and became Bhishma.
Worship
In Hindu tradition, the Pole Star, Dhruva Tara, is pointed out to newly married couples in the wedding ritual, as a symbol of the constancy of the marriage.