The Goddess who is worshipped during the famous Chhath Puja is known as Chhathi Maiya. Chhathi Maiya is known as Usha in the Vedas. She is believed to be the consort of Surya, the sun god. Some scholars believed that she is the only beloved of Surya and some suggest that she is Surya's wife.
The Sun, considered as the god of energy and of the life-force, is worshiped during the Chhath festival to promote well-being, prosperity and progress. In Hinduism, Sun worship is believed to help cure a variety of diseases, including leprosy, and helps ensure the longevity and prosperity of family members, friends, and elders. The rituals of the festival are rigorous and are observed over a period of four days. They include holy bathing, fasting and abstaining from drinking water (Vratta), standing in water for long periods of time, and offering prashad (prayer offerings) and arghya to the setting and rising sun.