The energy emitted by the Sun is produced in a very small region at: 

The sun's center

 Tremendous pressure is created at the Sun’s center due to its own gravity. The Sun is kept from collapsing by thermal pressure generated by:

nuclear fusion

 The existence in the Sun’s atmosphere of elements such as calcium is inferred from absorption lines in

 the photosphere and chromosphere

The photosphere (visible surface) of the Sun is like: 

a cloud. You would notice very little changes of its apparent surface changes as you went through it 

The ________ is the outermost, hottest part of the Sun’s atmosphere: 

the corona.

The temperature in and around the sun drops as you move from the core to the 

chromosphere then rises again

 The ______-year solar cycle is characterized by a variation in the number of sunspots AND reversal of the Sun’s magnetic field.

 22-Year

Sunspots appear dark because they are 

How would sunspots appear if you could magically seperate them from the Sun? 

The seen visible interaction of the solar wind with Earth’s magnetic field is 

the aurora

The sun is a stable as a star because 

gravity blances forces from pressure.

The proton-proton cycles involves what kind of fusion process? 

hydrogen into helium 

What is responsible for the increase in temperature of the corona?  

The sun’s magnetism

The number of sunspots and solar activity in general peaks 

every 11 years. 

The temperature of the layer of atmpsphere that produces the visible surface of the sun is 

5,800 K

By what mechanism does solar energy reach the sun’s photosphere from the layer just underneath it

Convectoin

What is the meaning of solar constant? 

Loops of glowing solar material seen sticking out from the solar limb during eclipses totality are called 

You can best model the size and distance of our sun and the next nearest star using 

two golf balls a few hundred km apart

The angle of stellar parallax for a star gets larger as the length of the 

baseline increases

A star’s proper motion is 

its annual apparent motion in the sky.

A star’s apparent magnitude is 

a number used to describe how our eyes measure its perceived brightness.

The absolute magnitude of a star is its brightness as seen from a distance of 

10 parsecs. 

Wien’s law (related to the black body curve) tells us that the 

hotter an object the shorter peak wavelength of its emitted light.

We can estimate the surface temperature of a star by using its 

color, the pattern of absorption lines, Wiens’ law differences in brightness as measures through blue and red filters. 

If the sun had the diameter of a tennis ball then the red supergiant Betelgeuse would have a diameter of 

Two stars have the same surface temp, but the radius of one is 100 times that of the other. 

What are the two most important intrinsic properties for classifying stars?.

 Luminosity and surface temp

Which property of a star would not change if we could observe it from twice as far away

color.

 Astronomers can estimate the size of a star using 

apparent brightness, direct observation of diameter, and temperature.

Stellar parallax is used to measure

 the distance of stars.

In the stellar magnitude system, invented by Hipparchus, a smaller magnitude indicates a 

brighter star.

Which of the following quantities do you need in order to calculate a star’s luminosity? 

Apparent brightness and distance to the star

Which spectral classification type corresponds to a star like the sun? 

G

Eclipsing binary stars are very useful for determining 

the masses of stars.

What is the single most important characteristic in determining the course of a star’s evolution? 

Mass

When a star’s visible light passes through interstellar dust, the light we see is 

dimmed and reddened. 

 The _________ of light passing through thin dust clouds lets us map the milky way galaxy’s magnetic field: 

polarization. 

Emission nebulae like M42 in Orion occur only near stars that emit 

large amounts of UV radiation.

An emission nebula appears primarily ________ in color, due to ionized hydrogen: 

red

What do “forbidden” lines reveal about interstellar space? 

The density and pressure of interstellar gas is much lower than can be produced in a lab on Earth

If one region of the sky shows nearby stars, but no distant stars or galaxies, our view is 

probably blocked by interstellar dark cloud of gas and dust

The Local Bubble was probably created by a nearby supernova perhaps 

What information does 21-c radiation provide about the gas cloud that emitted it? 

Radial velocity, density, temperature.

21-C radiation is important and useful because its radio waves

pass unaffected through interstellar dust

Of the given forms of radiation, visible radiation gives us the least accss 

to the Milky Way galaxy.