Astr 3- HW 6

Granules are:

• Cooler regions on the sun's photosphere caused by upwellings of the sun's magnetic field.

•  Cool regions on the photosphere where coronal holes allow energy to escape.

• Convective cells on the sun's surface, in the photosphere.

• Violent eruptions of material from the sun's surface near sunspots.

When we look at the sun through a filter centered on the Hα line we see:

• filaments

•  

  the chromosphere

• spicules

• prominences

•  all of the these.

Where is energy produced in the sun?

•  

  predominantly from plage regions on the photosphere

•  

  within the inner 25% of its radius

•  

  in the hot corona

•  

  within the inner 50% of its radius

What is the Maunder minimum?

•  

  The minimum temperature that a blackbody has for a given wavelength of peak intensity.

•  

  The minimum orbital period for an exoplanet.

•  

  The minimum temperature for any planet in the solar system.

•  

  The period of 100 years where there were very few sunspots on the sun.

What is the time interval between the maximum numbers of sunspots? (solar maximum to solar maximum)

•  

  32 years

•  

  12 hours

•  

  11 years

•  

   

  30 days

Which of the following is a manifestation of the second law of thermodynamics?

•  You cannot cool your house by opening the refrigerator door.

•  Engines are never perfectly efficient, there is always waste heat.

•  The universe tends toward a state of more disorder with time.

•  All of these choices.

•  Left unattended, your coffee will always cool, never heat up.

How is energy transported in the sun?

• Convection & radiation.

•  Conduction only.

•  Convection only.

•  Radiation only.

The average density of the sun is

• near that of Earth (6 gm/cm³)

• 140 gm/cm³

• slightly larger than that of water (1.4 gm/cm³)

• near that of lead (11 gm/cm³)

Hydrostatic equilibrium in the sun is the balance between

• the strong & weak nuclear forces.

• thermal pressure & gravity.

• gravity & centrifugal force.

•  

  the gravitational forces between two binary stars.

The interior of the sun is a

• liquid

• gas

• plasma

• solid