Digital ACT Science Practice Question #1832

Based on standard spectral classification (O, B, A, F, G, K, M from hottest to coolest), the correct ordering of these stars from highest to lowest surface temperature is: Experiment Context (Hertzsprung-Russell Stellar Data): Astrophysicists surveyed four representative stars, compiling surface temperatures (in Kelvin) and luminosities relative to the Sun (L_sun = 1.0): Table 26: - Star 1 (Betelgeuse): Surface Temp = 3,500 K; Luminosity = 100,000 L_sun; Spectral Class = M - Star 2 (Sun): Surface Temp = 5,800 K; Luminosity = 1.0 L_sun; Spectral Class = G - Star 3 (Sirius A): Surface Temp = 9,900 K; Luminosity = 25 L_sun; Spectral Class = A - Star 4 (Sirius B): Surface Temp = 25,000 K; Luminosity = 0.003 L_sun; Spectral Class = DA