Astronomy Chapter 10: Other Planetary Systems

Extrasolar planets have been discovered with average densities similar to:

Styrofoam, iron, and water

Statistical evidence suggests that about ________ percent of all stars have an approximately Earth-sized planet orbiting in a region around the star where water could exist as a liquid on the planet's surface.

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Which of the following methods has led to the most discoveries of extrasolar planet candidates?

Detecting the dip in measured brightness as the planet crosses our line of sight to the star

Which of the following methods has led to the most confirmed discoveries of massive planets orbiting near their parent stars?

Detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum

Which two quantities need to be measured in order to determine the density of an extrasolar planet?

Mass and radius

What is the most accurate way to measure the surface temperature of an extrasolar planet?

Measure the drop in total infrared light when the planet passes behind the star

The Doppler method can be used to estimate the semimajor axis of a planet's orbit by:

Measuring the time it takes for the star's line-of-sight velocity to cycle from peak to peak, and using Newton's version of Kepler's Third law.

This figure shows the orbital periods and radii of all planet candidates identified from Kepler data as of early 2013. Which of the following size planets were most detected? (Chart)

Planets between 1 Earth radius and 4 Earth radii in size

The planet HAT-P-32b has more than twice the radius of Jupiter, yet is only the same mass. It orbits its star more than a factor of ten closer than Mercury's orbit around the Sun. Which is the most plausible explanation for its large size?

Planets that are close to a star are puffed up and therefore larger

A transiting extrasolar planet is observed to block 1% of its host star's light. How does the size of this planet compare to the host star?

The planet's radius is 10% of the host star's radius

The depth of the dip in a star's brightness due to the transit of a planet depends most directly on:

The planet's size

The reason that most extrasolar planets discovered by the Doppler method are found close to their parent stars is:

The wavelength shift of the star's spectrum is larger

Why are many of the newly detected extrasolar planets called "hot Jupiters"?

Their masses are similar to Jupiter but they are very close to the central star and therefore hot