In a saucepan over medium-high heat, add the pears, sugar, 1 cup water, cinnamon, and star anise. Bring to a boil, reduce the heat, and simmer until the pears are soft, about 15 minutes. Let the pears and syrup cool in the pan. Once cool, strain through a fine-mesh sieve, then discard or reserve the solids for another use. Stir in the lemon juice and let cool completely.