Ch 8: The Sun
What is the average distance between the Sun and Earth?
1 AU
The corona can reach temperatures of up to ____.
2,000,000 K
Consider the complete magnetic cycle of sunspot activity on the Sun. Approximately how many years is this cycle?
22 years
What is the approximate average temperature of the Sun's surface?
5800 K
Why does the temperature of the corona rise with latitude?
Atoms within the corona become more ionized at higher altitudes
What causes granulation on the photosphere?
Convection
Of the following parts of the Sun, which is the hottest? a. photosphere b. sunspots c. chromosphere d. corona e. supergranules
Corona
The Babcock model of the solar magnetic cycle explains the sunspot cycle as primarily a consequence of the Sun's ____.
Differential rotation
When mapping the interior of the Sun, astronomers must measure _____ as the photosphere moves up and down.
Doppler shifts
Almost all the light we receive from the Sun escapes from underneath its photosphere. (T/F)
False
Sunspot numbers follow a seven-year cycle. (T/F)
False
The layer above the chromosphere is the photosphere. (T/F)
False
The visible surface of the Sun is composed of solid matter. (T/F)
False
What are the dark regions that give the Sun's photosphere a mottled appearance?
Granules
Which two elements are most abundant within the Sun?
Hydrogen and Helium
Granulation is evidence that energy in the photosphere ____.
Is flowing upward
What occurs on the surface of the Sun during a solar cycle minimum?
Little to no sunspot activity
Galileo proposed that the Sun is a rotating sphere after he ____.
Observed sunspots move across the surface of the Sun
Which is the correct order of the Sun's atmospheric layers, from the innermost to outermost?
Photosphere, Chromosphere, Corona
The temperature of the Sun is determined by measuring the __________ of sunlight.
Spectrum
Granulation is caused by convection currents just below the photosphere. (T/F)
True
Sunspots are parts of active solar regions dominated by magnetic fields that encompass all layers of the Sun's atmosphere. (T/F)
True
Sunspots tend to occur in groups, or pairs, with the magnetic field around the pair resembling that around a bar magnet. (T/F)
True
The Sun is a ball of hot gas held together by its own gravity. (T/F)
True
The corona is so dim that it is not visible in Earth's daytime sky. (T/F)
True
The upper chromosphere is hot enough to emit X-rays. (T/F)
True
Astronomers often record solar images in the ____ part of the electromagnetic spectrum because the gaseous layers high in the Sun's atmosphere are very hot and emit most of their light at short wavelengths.
Ultraviolet
Astronomers refer to the dark center of a sunspot as a(n) ____
Umbra
Astronomers can measure the magnetic fields of sunspots using the ____, which splits spectral lines into multiple components.
Zeeman effect
The pink color of the chromosphere is produced by the combined light of three emission lines of hydrogen: ____.
red, blue, violet
