Letters on Sunspots (Istoria e Dimostrazioni intorno alle Macchie Solari) was a pamphlet written by Galileo Galilei in 1612 and published in Rome by the Accademia dei Lincei in 1613. In it, Galileo outlined his recent observation of dark spots on the face of the Sun.[1] His claims were significant in undermining the traditional Aristotelian view that the Sun was both unflawed and unmoving.[2] The Letters on Sunspots was a continuation of Sidereus Nuncius, Galileo's first work where he publicly declared that he believed that the Copernican system was correct.[3]