Which of these are not associated with the active Sun?
Sunspots are dark splotches on the Sun. Which statement is true?
-They are associated with areas of very low magnetic fields.
-They are hotter than the surrounding areas of the Sun.
-They are extremely cold objects, as cold as Pluto.
-They are extremely hot, but cooler than the surrounding areas of the Sun.
-They are solid bodies floating on the surface of the Sun.
They are extremely hot, but cooler than the surrounding areas of the sun.
In the proton-proton cycle, the helium atom and neutrino have less mass than the original hydrogen. What happens to the "lost" mass?
It is converted to energy.
Which is the net result of the proton-proton chain?
4 protons = 1 helium 4 + 2 neutrinos + gamma rays
Consider the four stars shown following. Rank the stars based on their surface temperature from highest to lowest.
red supergiant star
orange main-sequence star
blue white dwarf star
highest: blue white dwarf star
orange main-sequence star
lowest: red supergiant star
Listed following is a set of statements describing individual stars or characteristics of stars. Match these to the appropriate object category.
A)red giant or supergiant
B)main sequence stars
1. The majority of stars in our galaxy
2. very cool but very luminous
3. not much larger in radius than Earth
4. very hot but very dim
5. the Sun, for example
6. found in the upper right of the H-R diagram
7. a very hot and very luminous star
A) 2, 6
B) 1, 5, 7
C) 3, 4
Compared to a main-sequence star with a short lifetime, a main-sequence star with a long lifetime is
less luminous, cooler, smaller, and less massive than a main-sequence star with a short life time
Compared to a high-luminosity main-sequence star, stars in the upper right of the H-R diagram are
cooler and larger in radius
Compared to a low-luminosity main-sequence star, stars in the lower left of the H-R diagram are
hotter and smaller in radius
Star A appears brighter than star B, as seen from Earth. Therefore, star A must be closer to Earth than star B. T or F
Astronomers can distinguish between main-sequence and giant stars purely by spectroscopic means. T or F
Two stars have the same absolute magnitude, but one lies twice as far from Earth as the other. It will appear half as bright. T or F
Why does the same side of the Moon always face Earth?
Tidal forces from Earth slowed the Moon's rotation on it's axis.
Which of the following statements is true?
a. The sun appears to rise before it actually reaches the horizon.
b. The Sun appears to set before it actually reaches the horizon.
c. It is completely dark for six months at the North Pole during the winter.
d. All of the above.
e. None of the above.
When compared with lower frequency waves of light, higher frequency waves of light have
Nathan is four feet away from a light bulb. Jacob is eight feet away from the same bulb. How much brighter is the bulb to Nathan than it is to Jacob?
four times as bright
We can see the photosphere because
it is the first layer of the Sun in which emitted photons have a chance to leave the Sun
The blackbody radiation from a star can be used to
measure the temperature of the surface of the star