Which of These Provides a Plausible Method to Measure the Mass

question 88

Multiple Choice

Which of these provides a plausible method to measure the mass of an exoplanet?

• A) We use Newton's law of gravity, using the measured distance of the planet from its star and the planet's gravitational pull on the star.
• B) We cannot make any firm estimate of the mass of an extrasolar planet with present technology.
• C) We use spectra to measure the planet's temperature and photometry to measure its brightness.
• D) We measure the planet's angular diameter and hence its size and then use spectra to find its composition and hence density.