Chapter 13 – Quiz 13 – Flashcards

Based on everything you have learned about the formation of our solar system, which of the following statements is probably not true? Other solar systems will also have planets in the two basic categories of terrestrial and jovian. Only a tiny percentage of stars are surrounded by spinning disks of gas during their formation. Other planetary systems will have far more numerous asteroids and comets than actual planets. Planets always tend to orbit their star in the same direction and approximately the same plane.

Assuming that our ideas about how "hot Jupiters" ended up on their current orbits are correct, why didn't our own solar system end up with any hot Jupiters? The existence of Earth and the other terrestrial planets prevented the jovian planets from migrating inward. Our solar nebula must have been blown into space shortly after the formation of the jovian planets. Our solar nebula must have stuck around for an unusually long time after the formation of jovian planets. Our jovian planets must have migrated outward from inside the orbit of Mercury.

In general, which type of planet would you expect to cause the largest Doppler shift in the spectrum of its star? a massive planet that is close to its star a massive planet that is far from its star a low-mass planet that is close to its star a low-mass planet that is far from its star

Suppose a planet is discovered by the Doppler technique and is then discovered to have transits. In that case, we can determine all the following about the planet except ______________. its rotation period its orbital period its physical size (radius) its precise mass its density

All the following statements about known extrasolar planets are true. Which one came as a surprise to scientists who expected other solar systems to be like ours? In some cases, we've found more than one planet orbiting the same star. Some of the planets orbit their star more closely than Mercury orbits the Sun. Most of the planets are quite massive - much more like Jupiter than like Earth. Most of the planets orbit stars that are quite nearby compared to the scale of the entire Milky Way Galaxy.

In essence, most of the extrasolar planets discovered to date have been found by: Closely examining very high-resolution photographs of other star systems. Observing a star carefully enough to notice that it is experiencing a gravitational tug caused by an unseen planet. Observing mini-eclipses of a star as an unseen planet passes in front of it. Identifying spectral lines that look like what we expect to see from a planet rather than a star.

You observe a star very similar to our own Sun in size and mass. This star moves very slightly back and forth in the sky once every 4 months, and you attribute this motion to the effect of an orbiting planet. What can you conclude about the orbiting planet? The planet must have a mass about the same as the mass of Jupiter. You do not have enough information to say anything at all about the planet. The planet must be closer to the star than Earth is to the Sun. The planet must be farther from the star than Neptune is from the Sun.

Current evidence suggests that many massive jovian planets orbit at very close orbital distances to their stars. How do we think these planets ended up on these close orbits? These planets migrated inward after being born on orbits much farther from their stars. These planets are jovian in nature and were able to form close to their stars because their solar nebulas were very cold in temperature. These planets were captured from other solar systems. Despite their large masses, these planets are terrestrial in nature and therefore could form in their inner solar systems.

Why is it so difficult to take pictures of extrasolar planets? No telescope is powerful enough to detect the faint light from a distant planet. Their light is overwhelmed by the light from their star. Extrasolar planets give off light at different wavelengths than planets in our solar system. Telescopes are too busy with other projects.

When is the soonest we are likely to have images and spectra of Earthlike planets around other stars? In a decade or two, through space missions now in the early planning stages. Any day now, thanks to new, large, ground-based telescopes. In just a few years, through the Kepler mission. We already have images and spectra of Earthlike planets around other stars.

The astrometric technique looks for planets with careful measurements of a star's _________. velocity towards or away from us brightness position in the sky all of the above

Which of the following is not expected for a "hot Jupiter" that orbits 0.05 AU from its star cloudtop temperatures over 1000 K intense volcanism density similar to or lower than Jupiter's clouds made of rock dust

To date, we've found very few planets orbiting their stars at distances comparable to the distances of the jovian planets in our solar system. Why do astronomers think this is the case? Planets at such distances are extremely rare. Planets at such distances are probably very low in mass. We have not yet been searching for planets at such distances for a long enough time. No known technique can detect planets at such large distances.

Suppose you are using the Doppler technique to look for planets around another star. What must you do? Carefully examine a single spectrum of an orbiting planet. Compare many spectra of the star taken over a period of many months or years. Carefully examine a single spectrum of the star. Compare many spectra of an orbiting planet taken over a period of many months or years. Compare the brightness of the star over a period of many months or years.