Astro quiz 15

Astronomers have found that the level of the Sun's activity varies over the centuries. How did they come to realize that this is so?

>all of the above historical records of the number of sunspots seen on the Sun historical records of auroral activity measuring the amount of radioactive carbon in tree rings

What is the best reason astronomers have come up with to explain why sunspots are cooler and look darker?

Sunspots are places where the strong magnetic fields in the Sun resist the upward motion of bubbling hot gases from underneath

Which statement about the Sun's rotation is TRUE?

The Sun rotates at different rates at different latitudes on the Sun.

Astronomers have concluded that the Sun's activity varies in an 11-year cycle. Which of the following statements about this cycle is TRUE?

The number of sunspots gets larger and smaller over the course of 11 years.

Solar wind particles can be captured by the Earth's magnetosphere. When these particles spiral down along the magnetic field into the atmosphere they are responsible for

aurorae

Astronomers first detected the presence of a wind of particles coming from the Sun by

by dramatic and sudden changes in the spectrum of the corona

Coronal Mass Ejections from the Sun have many serious effects on or near the Earth. Which of the following is NOT one of these effects?

causing huge cyclones around the equator of the Earth

The hottest zone in the Sun is the

core

Which part of the Sun's atmosphere has the lowest density of atoms?

corona

The ten million tons of particles that escape the Sun each year in the form of the solar wind get out mainly through regions called

coronal holes

The Sun's chromosphere and corona were discovered ...

during total eclipses of the Sun

The most common element in the Sun is

hydrogen

As astronomers have learned more abou thte structure of the Sun they have found that it

is made entirely of hot gas

Astronomers now realize that active regions on the Sun are connected with

loops of magnetic field emerging from the surface of the Sun

If you were to glance up at the Sun (which you should not do) the part of the Sun that you can see directly is called its

photosphere

The Sun's chromosphere contains many jet-like projections that stick up into the transition region. These spikes of gas are called

spicules

What mechanisms do astronomers believe is responsible for making the Sun's outer atmosphere so much hotter than its photosphere?

the Sun's magnetic field (interacting with the charged particles) heat up the atmosphere

As you go upwards from the Sun's photosphere

the density (number of atoms in a unit volume) decreases

The Sun's photosphere is

the part of the Sun from which the light comes that we see when we look at the Sun with our eyes

Sunspots are darker than the regions of the Sun around them because

they are cooler than material around them (although still very hot compared to Earth temperatures)

How do astronomers know what the outer layers of the Sun are made of?

we take an absorption line spectrum of the Sun and the absorption lines tell us what elements are present in the outer layers