This question is about analysing the electromagnetic radiation from the star Psi Tauri in the Milky Way galaxy.
The peak wavelength of electromagnetic radiation from Psi Tauri is 410 nm410 \text{ nm}410 nm. The surface temperature of the Sun is 5800 K5800 \text{ K}5800 K and the wavelength at which its maximum intensity is emitted is 500 nm500 \text{ nm}500 nm.
The luminosity of Psi Tauri is 1.8×1028 W1.8 \times 10^{28} \text{ W}1.8×1028 W.
Show that the surface temperature of Psi Tauri is approximately 7100 K7100 \text{ K}7100 K.
Estimate the radius of Psi Tauri.
Electromagnetic radiation is collected from Psi Tauri by a sensor on Earth with an efficiency of 15%15\%15% and cross-sectional area 2.0×10−4 m22.0 \times 10^{-4} \text{ m}^22.0×10−4 m2. The radiant power detected by the sensor is 4.5×10−15 W4.5 \times 10^{-15} \text{ W}4.5×10−15 W.
Calculate the intensity (radiant power per unit area) of the radiation arriving at the sensor from Psi Tauri.
Calculate the distance of Psi Tauri from Earth in light years.
66 exam-style questions on OCR A A Level Physics Astrophysics and cosmology, covering Stars, Electromagnetic radiation from stars, and Cosmology. Each one has a worked solution and a mark scheme showing where the marks go.