Question: how dhruva became a star?
Answer: ' But Dhruv only smiled when he saw Narayan. So Vishnu turned Dhruv into a little star and placed him high in the sky, above the world, and away from all jealousy and evil. He turned the Seven Rishis, who had protected Dhruv as he prayed, into stars as well, and placed them protectively around the little Dhruv-star.