Chandrabhaga was the daughter of a sage. Surya fell in love with her. She refused the advances and plunged into a river that Surya named after her.
His son Samba caused a lot of trouble to Krishna. The day came that he cursed him for contracting leprosy. Jambavati, his mother, could not bear the pain and asked Krishna to free Samba from the curse.
Krishna told him to pray to Surya and take a bath in the Chandrabhaga river. Then he was healed. But Samba could no longer run, Krishna carried him to the Chandrabhaga. Samba was cured.