USAAAO — 2025 First Round

Evan uses a telescope of focal distance f = 1000 mm to observe a star known to have a parallax p = 50 mas. Observing the CCD of the telescope, Evan notices that the star has a diameter D = 0.1 µm. Furthermore, he measures its apparent magnitude to be m = 1. What is the approximate temperature of this star? Please, neglect the atmospheric seeing in your calculations.