How Do We Measure the Mass of an Extrasolar Planet

question 43

Multiple Choice

How do we measure the mass of an extrasolar planet?

• 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 measure the change in the brightness of a distant star that the planet causes by microlensing.
• 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.

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