Exam 10: Other Planetary Systems: the New Science of Distant Worlds

A star is seen to have two transiting planets. Planet 1 transits every 3 months, and Planet 2 transits every 15 months. What can we infer about their orbits?

What could happen in planetary systems where the nebular gas is quickly disbursed?

In the searches so far, only about 1 in 10 stars show evidence for planets around them.

What are the two primary methods by which planets have been found around other stars in our galaxy? I)Direct images in visible and infrared light II)Indirectly by detecting the motion of the host star III)Indirectly by measuring the drop in brightness of the host star when the planet crosses our line of sight

A star with planets orbiting in a plane that is not face- on to our line- of- sight exhibit a Doppler effect due to .

Consider two main sequence K- stars of equal mass. Each star has been measured for a periodic wobble in its velocity curve, with one having a period of 1 month and the other having a period of 2 months. Which star has the closest planet (the planet with the smallest orbit)?

According to Kepler results in mid- 2013, what fraction of stars host an Earth- size planet?

A planet's size can be determined by observing its transit across a star.

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

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

How can astronomers measure the period of a planet's orbit?

Most of the planets discovered around other stars have masses comparable to the terrestrial planets in our own solar system.

As of the time of the publication of the textbook, how many planet candidates have been discovered using the transit method?

Why is it so difficult to make a direct image of a planet around another star?

You are measuring how velocity changes with time of two stars like the Sun in order to detect their planets. Both stars have a velocity curve with a period of 2 years, but the maximum size (peak- to- peak amplitude)of the velocity curve of star A is 100 km/s, and for star B it is 200 km/s. What causes this difference? Assume the planets are named after their stars.

Direct detection of an extrasolar planet means .

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?

The first planets around other Sun- like stars were discovered

Hot Jupiters were a surprise to astronomers. What is the current explanation for their existence?

What is the transit method of finding extrasolar planets?