order of red giant's life
Red Giant ? Planetary Nebula ? White Dwarf ? Black Dwarf
or
Red Giant ? Type II Supernova ? Neutron Star
or
Red Giant ? Type II Supernova ? Black Hol
The eventual fate of our Sun is to
become a steadily cooling white dwarf.
Our Sun will not become a nova because this only happens to stars
with a binary companion.
Black holes are formed by
supernovae from the most massive stars.
Which of the following lists, in the correct order, a possible evolutionary path for a star?
Red Giant, Planetary Nebula, White Dwarf
For a white dwarf to become a nova it is necessary for it to
have a binary companion.
Imagine that you could travel at the speed of light. Starting from Earth, how long would it take you to travel to the center of the Milky Way Galaxy?
25,000 years
approximate distance from the sun to the center of the Milky Way
25,000 ly
Where is our Sun located in the Milky Way Galaxy?
about half way between the center and the outer edge
Which of the following correctly lists objects from largest to smallest?
Local Group, Galaxy, Nebula, Star
Fifteen years ago, a quasar was observed that was found to be located 8 billion light years
away. If our universe is approximately 15 billion years old, when did the quasar emit the light that we observe?
8 billion years ago
Your satellite orbits close to the Sun and detects a solar flare erupting at 10:00 PM, as
measured by the satellite's clock. Your clock is exactly synchronized with the satellite clock. The Sun is located 8 light minutes away from Earth. If you wish to ob
10:08 PM.
Imagine that you simultaneously receive the satellite transmission of two pictures of two
people that live on planets orbiting two different stars. Each image shows the people at their 21st birthday parties. Consider the following possible interpretations
The person that is farther from you is actually the older of the two people.
According to modern ideas and observations, what can be said about the location of the
center of our expanding universe?
The universe does not have a center.
If our universe is expanding, what are the implications for the separation between two stars within our galaxy?
The distance between the two stars is unaffected.
Which of the following conclusions can you draw about the expansion of the universe from the drawing shown?
All galaxies appear to move away from each other during the expansion of the universe.
You observe a star rising due east. When this star reaches its highest position above the
horizon, where will it be?
high in the southern sky
How much of the celestial sphere can an Earth observer see at one time?
exactly half
You are observing the sky from your southern hemisphere location in Australia. You see a
star rising directly to the east. When this star reaches its highest position above the horizon, where will it be?
high in the northern sky
Stars that never appear to set are called circumpolar. As you move from Earth's equator toward the North Pole, the number of stars that are circumpolar
increases.
Imagine you are standing somewhere on the Equator. Of the stars that you can see,
roughly how many of these stars are circumpolar?
none
Imagine you are standing in the northern hemisphere. Looking directly north, you see a star just above the horizon. A little later you notice that it has shifted position slightly. Which way did it move?
to the right, (east)
You are looking toward the north and see the Big Dipper to the right of Polaris. Fifteen
minutes later, the Big Dipper will appear to have moved in roughly what direction?
up (away from the horizon)
How much time is there between when a star rises and when it sets?
it depends on the star
You go out tonight and see the brightest star in the constellation Orion just rising above your eastern horizon at 10 PM. One week later at 10 PM this same star will be
slightly higher in the sky.
One night, you see the star Sirius rise at exactly 7:36 PM. The following night it will rise
slightly earlier.
One evening at midnight, you observe Leo high in the southern sky at midnight. Virgo is to the east of Leo and Cancer is to the west. One month earlier, which of these constellations was high in the southern sky in at midnight?
Cancer
What component of Earth's motion causes the stars to rise earlier on successive nights?
its orbit around the Sun
Through how many degrees does Earth rotate in exactly 24 hours?
more than 360
Which takes longer to complete?
one solar day
Image that Earth begins orbiting the Sun twice as fast while maintaining the same rotation
rate. It now orbits once around the Sun every 6 months. In this case, what happens to the
length of the solar day?
It gets slightly longer.
Imagine that Earth stops orbiting the Sun but continues to rotate in place about its own axis
at its current rate. In this case, what happens to the length of the solar day?
It gets shorter.
In the celestial sphere model, the Sun's position is constantly changing; the path that it follows is called the ecliptic. About how long does it take the Sun to complete one trip around the ecliptic?
365 days
In the celestial sphere model, the Sun's position along the western horizon at sunset
changes because
the position of the Sun along the ecliptic is constantly changing.
After the Sun leaves the constellation Sagittarius, how long until it returns to this
constellation?
one year
How often is the Sun directly over Earth's equator?
once every six months
If the Sun's motion along the ecliptic were reversed, how would its daily motion appear?
It would continue to rise in the east and set in the west.
Which of the following statements is true about the location of the Sun at sunrise during the middle of winter?
The Sun will rise south of east.
Which of the following statements is true about the location of the Sun at sunset during the middle of summer?
The Sun will set north of west.
If it is summertime right now, how does the altitude of the noontime Sun change (if at all) as winter approaches?
It decreases.
During the full moon phase, how much of the Moon's surface is being illuminated by
sunlight?
half
When the Moon appears to completely cover the Sun (a solar eclipse), the Moon must be at
which phase?
new
Which of the following best describes the reason for the appearance of the Moon at different times of the month?
The angle between Earth and the Moon lets us see different amounts of the lit Moon.
The stars Antares and Mimosa each have the same luminosity. Antares is cooler than Mimosa. Which star is larger?
Antares
Rigel is much more luminous than Sirius B. Rigel and Sirius B have the same temperature.
Which star has the greater surface area?
Rigel
You observe two stars with the same luminosity and determine that one is larger than the other. Which star has the greater temperature?
the smaller star
If the stars Betelgeuse and Rigel each have the same luminosity, but the temperature of
Betelgeuse is lower than Rigel, which star has the greater surface area?
Betelgeuse
You observe a very large and very hot star in the constellation Orion. On the same night,
you observe another star in Orion that is much smaller but has the same temperature. Which star is more luminous?
the larger star
Imagine you are observing two stars. One star is hot and small and the other star is cooler
and larger. Which star is more luminous?
There is insufficient information to answer this question.
A lump of lead is heated to a high temperature. Another lump of lead that is twice as large is heated to a lower temperature. Which lump of material appears bluer?
The hotter lump appears bluer.
Which of the following spectra is produced by the Sun?
dark line absorption spectrum
If you analyze the light from a low density object (such as a cloud of interstellar gas), which type of spectrum do you see?
bright line emission spectrum
Imagine that you observe the Sun while in your space ship far above Earth's atmosphere.
Which of the following spectra would you observe by analyzing the sunlight?
dark line absorption spectrum
Imagine that you are on the surface of Earth (below the atmosphere) and are observing the
Sun. Which of the following spectra would you observe by analyzing the sunlight?
dark line absorption spectrum
Which of the following wavelengths can be observed easily by a telescope located on Earth's surface?
radio
Which of the following wavelengths of light emitted by the Sun is most effectively blocked by Earth's atmosphere?
gamma
Imagine that you are the head of a funding agency that can afford to build one telescope.
Which of the following proposed telescopes would be best to support?
an ultraviolet telescope in orbit around Earth
Some telescopes are placed in space above Earth's atmosphere primarily for which of the
following reasons?
The light from stars can be blocked by Earth's atmosphere.
Where would you look to see a planet rise when it is in retrograde motion?
near the eastern horizon
A planet moving in retrograde motion will, over the course of one night, appear to
move east to west.
A planet is moving in retrograde motion. Over the course of several nights, how will the
planet appear to move relative to the background stars?
east to west
A planet is moving in normal motion. Over the course of several nights, how will the planet appear to move relative to the background stars?
west to east
Imagine that you are viewing a star that has an apparent magnitude of 0.2 and is located about 100 parsecs away from us. Which of the following is most likely the star's absolute magnitude?
-4.8 (Most negative number)
Star G has an apparent magnitude of 5.0 and an absolute magnitude of 4.0. Star H has an
apparent magnitude of 4.0 and an absolute magnitude of 5.0. Which of the following
statements is true about viewing these two stars from Earth?
Star H will appear brighter than Star G.
Vega has an apparent magnitude of 0.03 and an absolute magnitude of 0.58. If it were
moved twice as far from Earth as it is now, which of the following would occur?
apparent magnitude number would increase
Pollux has an apparent magnitude of 1.1 and an absolute magnitude of 1.1. Epsilon Eridani
has an apparent magnitude of 3.72 and an absolute magnitude of 6.1. From which of these stars do we receive more light at Earth?
Pollux
Star A has an apparent magnitude of 1.0 and an absolute magnitude of 1.0. How would the
apparent and absolute magnitudes of this star change if the distance between Earth and the
star were decreased?
The apparent magnitude number would decrease, and the absolute magnitude
number would not change.
You observe two stars over the course of a year (or more) and find that both stars have
measurable parallax angles. Star X has a parallax angle of 1 arcsecond. Star Y has a parallax angle of � an arcsecond. Which star is closer?
Star X
On Earth, the parallax angle measured for the star Procyon is 0.29 arcseconds. If you were
to measure Procyon's parallax angle from Venus, what would the parallax angle be? (Note: Earth's orbital radius is larger than Venus's orbital radius.)
less than 0.29 arcseconds
Consider two stars (X and Y). If star X is 3 parsecs away and star Y is 5 parsecs away,
which has the greater parallax angle?
Star X
What is the distance to a star (in parsecs) that has a parallax angle of 0.1 arcseconds?
10
Star X is 10 parsecs away, and star Y is 50 parsecs away. Which star has a greater
parallax angle?
Star X
Star X is 10 parsecs away, and star Y is 50 parsecs away. What is the parallax angle for
Star X?
1/10 an arcsecond
Star X is 10 parsecs away, and star Y is 50 parsecs away. What is the maximum separation angle between the endpoints for Star Y?
1/25 an arcsecond
To measure a star's parallax angle accurately, you should observe a star's location against
background stars
on many nights over the course of a year.
You observe two stars over the course of a year (or more) and find that both stars have
measurable parallax angles. Star X has a parallax angle of 1 arcsecond. Star Y has a
parallax angle of � an arcsecond. How do the distances to the two stars compare?
Star X is twice as far away as star Y.
Star A has absolute magnitude of -8.1 and belongs to spectral class B8. Star B has absolute magnitude of 11.2 and also belongs to spectral class B8. Which star has the greater surface temperature?
They have the same temperature.
A red giant of spectral type K9 and a red main sequence star of the same spectral type have
the same
temperature.
The two axes on the Hertzsprung-Russell (H-R) diagram can be
luminosity and temperature.
On an H-R diagram, stars at the same temperature are found
aligned vertically (i.e., one above the other).
On an H-R diagram, stars with the same luminosity are found
aligned horizontally (i.e., next to each another).
sequences of spectral classes represent the coolest to hottest stars
MKGFABO
Which of the following statements is always true of two stars that have the same absolute
magnitude?
They have the same luminosity.
Star F is known to have an apparent magnitude of -26 and an absolute magnitude of 4.0. The distance to Star F is
much less than 10 pc.
How does the Sun produce the energy that heats our planet?
Hydrogen atoms are combined into helium atoms inside the Sun's core. Small amounts of mass are converted into huge amounts of energy in this process.
Main sequence stars begin life as
a cloud of gas and dust.
Star A will be a main sequence star for 45,000 million years.
Star B will be a main sequence star for 70 million years.
Star C will be a main sequence star for 2 million years
*Which has the greatest mass?
Star C has the greatest mass.
Which of the following statements best describes how the lifetimes compare between a star that has a mass equal to the Sun and a star containing three times more mass than the Sun?
The star with the same mass as the Sun will live more than three times longer than
the other star.