Our Evolving Universe
Self Test 14

1. Astrometric methods for discovering planets would favour
   1. massive planets orbiting close to stars near the Sun
   2. massive planets orbiting far from stars, distance immaterial
   3. massive planets orbiting far from stars near the Sun
   4. massive planets orbiting close to stars, distance immaterial
   
   
2. Spectroscopic (Doppler shift) methods for discovering planets favour
   1. massive planets orbiting close to stars near the Sun
   2. massive planets orbiting close to stars, distance immaterial
   3. massive planets orbiting far from stars near the Sun
   4. massive planets orbiting far from stars, distance immaterial
   
   
3. Doppler shift methods cannot measure
   1. the orbital period of the planet
   2. the distance of the planet from the star
   3. the mass of the planet (only an upper limit)
   4. the mass of the planet (only a lower limit)
   
   
4. We believe that the planets discovered are planets and not brown dwarfs because
   1. they have nearly circular orbits
   2. we know that many of them are not massive enough to be brown dwarfs
   3. they orbit too close to their stars to be brown dwarfs
   4. they do not have the right chemical composition for brown dwarfs
   
   
5. Planets around stars in globular clusters are unlikely because
   1. the stars in globular clusters are too low in mass to have planets
   2. the stars in globular clusters are too low in heavy elements
   3. the stars in globular clusters are too high in heavy elements
   4. stars in globular clusters are too massive

out of 5.

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