No, a star cannot turn into a planet. Stars and planets are two distinct types of celestial objects with different formation processes and characteristics.
Stars are massive, hot, and primarily composed of hydrogen and helium. They generate energy through nuclear fusion in their cores, producing light and heat.
Planets, on the other hand, are much smaller and cooler than stars, and they do not undergo nuclear fusion.
Stars form from the gravitational collapse of gas and dust in interstellar clouds, while planets are formed from the leftover material around a young star, known as a protostar, during the process of planetary accretion.
Therefore, while stars and planets are related in the sense that they can both be found in solar systems, they do not transform into one another.