Extinction by the Interstellar Medium Dims Starlight by About 2

question 35

Multiple Choice

Extinction by the interstellar medium dims starlight by about 2 magnitudes for every 1000 pc the light travels.What fraction of the photons remains from a star that is 5000 pc from an observer?

• A) 1/10
• B) 1/5
• C) 1/25
• D) 1/10,000
• E) 1/100