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Worksheetsastronomy
Total questions: 157
Worksheet time: 26hrs 10mins
The stars always set at the same angle everywhere on Earth
true
false
How long do the stars take to complete a full circle across the sky?
approximately 24 hours
more than 24 hours
less than 24 hours
How long does the Sun take to complete a full circle all the way around the sky?
approximately 24 hours
less than 24 hours
more than 24 hours
In which direction does the Sun generally move across the sky, hour by hour?
From West to East
From North to South
From South to North
From East to West
In which direction do the stars generally move, hour by hour?
From West to East
From North to South
From South to North
From East to West
Which of the following hypotheses is both falsifiable and testable?
The universe is dominated by something called "dim matter." Although it doesn't interact with light, it does have a gravitational influence on surrounding objects
The universe is dominated by particles called "invisitrons." They are massless and don't emit or absorb light. In fact, they are undetectable in every way.
You are stargazing while standing exactly at the North Pole on Earth. You see a relatively bright star several degrees above the horizon. When will this star set?
never
6 hour later
23 hr, 56 min, 4 s later
1 hour later
While stargazing one night from High Point, you see the star "Rigel" rising in the East, just barely above the horizon. Approximately how long will you have to wait for Rigel to reach its highest position in the sky?
1 year
10 minutes
23 hr, 56 min, 4 s
6 hour
Why do we experience seasons on the Earth?
The asterism (pattern of stars) called the "Summer Triangle" is visible in the summer months, and this heats the Earth.
The Sun's North-South position on the ecliptic changes throughout the year because the ecliptic is tilted.
The Sun is closer to Earth in the summer, farther away in the winter.
Where would you look in the sky to see a FULL moon at NOON?
High in the sky, nearly overhead
Setting in the West.
It's not visible in the sky at that time
Rising in the East.
Where will you always find a new moon in the sky?
90 degrees away from the sun
Opposite the sun
Next (near) to the sun
Which of the following is NOT one of the official moon phases
Full
First Quarter
Third Quarter
Old
Old
What is an ecliptic?
The name for a circle that is squished into an oval shape
The apparent path the Sun, moon, and planets roughly take as they drift across the background stars in the sky.
A special constellation in the night sky where the Sun can be found the first day of fall.
Where will you always find a full moon in the sky?
Opposite the sun
Next (near) to the sun
90 degrees away from the sun
The Sun, the moon, and a bright star are all together in the sky and rise in the East at the same time. Which of the three objects will set in the West FIRST, later that day?
The star will set first
The Sun will set first
They will all set at the same time
What time does the 3rd quarter moon RISE? (Assume you're observing from HPU)
Noon (12pm)
Midnight (12am)
Sunset (~6pm)
Sunrise (~6am)
Which of the following do NOT constitute a good scientific hypothesis? Select all that apply. (NOTE: this has nothing to do with how weird or ridiculous a hypothesis might sound; consider all available methods at our disposal in 2021 to test or falsify models.)
There is a group of particles in the Universe called "invisitrons" that are undetectable in every way possible (invisible, doesn't interact with light or matter, etc.).
There is a group of particles in the Universe called "invisitrons" that are undetectable in every There is a group of particles in the Universe called "whatevertrons" that are invisible, but they do interact with matter gravitationally (they tug on other objects because of their gravity)
The universe is actually part of a "Multiverse" (set of multiple universes) with which we can have no contact at all.
The Earth is flat.
The moon is made entirely of cheese.
Looking West at sunset, you notice a bright planet close to the Sun in the sky. The next night, you find that the planet has moved WESTWARD with respect to the background stars. Which planet(s) could you be looking at? Select all that apply.
Venus
Saturn
Mercury
Mars
Jupiter
Which list of moon phases below is in the correct chronological order, when read from left to right?
1st Quarter Moon, New Moon, 3rd Quarter Moon, Full Moon
New Moon, 1st Quarter Moon, Full Moon, 3rd Quarter Moon
New Moon, Full Moon, 1st Quarter, 3rd Quarter
Full Moon, 1st Quarter, New Moon, 3rd Quarter
What is the most direct cause of Earth's four seasons? (Choose the most accurate explanation of those provided.)
The changing position of the Moon with respect to the Sun and Earth.
The changing North-South position of the Sun in the sky throughout the year.
The changing luminosity of the Sun (more luminous in summer, less luminous in winter).
The changing Earth-Sun distance during the year (Earth is closer to Sun in summer, farther away in winter).
If the sun takes 365 days to circle completely around the ecliptic, what is its approximate angular speed in the Eastward direction with respect to the background stars? (You can do this without a calculator.)
1 deg/day
24 deg/day
0.0027 deg/day
day56 deg/day
2 deg/day
One sidereal day, the time it takes the stars to return to the same relative position night after night, is closest to which of the following? (assume you're on Earth)
23 hours, 56 minutes, 4 seconds
12 months
1 year
23.5 days
24 hours
A solar eclipse occurs: (choose the most correct answer)
whenever there is a NEW moon AND the moon is on the ecliptic.whenever the Sun is between the moon and Earth.
whenever the Sun is between the moon and Earth.
whenever there is a NEW moon.
Solar eclipses are never visible on Earth..
whenever there is a FULL moon.
You go outside one night ("Night A") and see the moon high in the sky, almost directly overhead. Very close to the moon you see Saturn; both are close to a bright star. The next night ("Night B") you observe Saturn again and notice it has moved WESTWARD with respect to the bright star. Approximately what time did the moon rise on the first night ("Night A")? Assume you were observing both nights from High Point, NC.
Sunrise (~6am)
Sunset (~6pm)
midnight
noon
If the circumference of the earth is 24000 miles (approximately true) and the earth rotates once every 24 hours (also approximately true), what is the speed of a person standing at the equator due to the rotation of Earth? Answer in miles per hour (mph). (NOTE: Type your answer WITHOUT commas and WITHOUT the UNITS) (OTHER NOTE: You should be able to do this in your head, without a calculator!)
(a)
Choose the latitude on Earth this star trail picture was most likely taken at:
+90 deg (North Pole)
+5 deg (near the equator)
-45 deg
-90 deg (South Pole
From the list below, choose the exposure time that is closest to the exposure time used to make this star trail image:
2 hours
30 minutes
6 hours
1 hour
12 hours
Which of the following are TRUE statements concerning lunar phases and eclipses. Select all that apply. (NOTE: Pretend you are observing from HPU)
The new moon rises and sets when the sun does.
A third quarter moon occurs approximately 1 week AFTER a new moon.
Lunar eclipses only occur near the full moon phase.
A full moon can rise at midnight.The moon is NEVER visible in the sky during the daytime
Where in the sky would you find a 1st quarter moon at midnight? (Assume you're observing from High Point University)
East, near the horizon (rising)
West, near the horizon (setting)
Overhead, high in the sky (near the meridian).
The 1st quarter moon is not visible then.
TRUE or FALSE: If you watch the sky over several hours one day/night, you will find that ALL objects (sun, moon, stars, planets) move from East to West.
true
false
The Sun, the moon, and a bright star are all together in the sky and rise in the East at the same time. Which of the three objects will set in the West FIRST, later that day?
The Sun will set first.
The star will set first.
They will all set at the same time.
The moon will set first
Explain how the zodiacal constellations are different from the other constellations.
The zodiacal constellations do not intersect with the ecliptic, while all other constellations do.
The zodiacal constellations intersect with the ecliptic, while all other constellations do not.
The zodiacal constellations can only be seen from either the northern or southern hemisphere, while all other constellations can be seen from both hemispheres
.The zodiacal constellations can be seen from both the northern and southern hemispheres, while all other constellations can only be seen from one hemisphere
From where on Earth could you observe all of the stars during the course of a year?
the north and south poles
the equator
This is not possible anywhere on Earth
the tropics of cancer and capricorn
What fraction of the sky can be seen from the North Pole?
0%
23.5%
50%
100%
Mars, Jupiter, and Saturn certainly appear to move backwards against the stars during retrograde motion, as observed from Earth, but are those planets ACTUALLY reversing direction and moving backwards in the solar system? (Assuming the heliocentric model is correct.)
No, they are always moving in the same direction in their orbit; they just appear to move backwards from our perspective as we 'lap' them in orbit.
Yes, they are indeed momentarily changing directions in their orbit as they move.
What ancient philosopher influenced thinking and biased scientific models for hundreds - if not thousands - of years?
Caeser
Billie Eilish
Genghis Khan
Aristotle
If the moon were to move a little farther away from Earth, what would happen to its orbital period?
It would decrease (take less time to orbit).
Its orbital period would not change.
It would increase (take longer to orbit).
What prediction do both the geocentric and heliocentric models make about the outer planets (Mars, Jupiter, Saturn) while they're in retrograde motion?
They should be a little fainter.
They should be a little brighter.
They are too close to the Sun to see then.
They should disappear from view for a few weeks.
What shape best describes the orbits of the planets?
Ellipses
Thor's Helmet
Circles
TRUE or FALSE: Both the geocentric and heliocentric models of the universe can explain retrograde motion.
true
false
The image below shows the location of the Sun and several constellations at noon on a particular day. (On this day, the Sun is in Gemini.) Which constellation will the Sun mostly likely be in, a few hours later on that same day?
Aries
Leo
Gemini
Taurus
Cancer
The image below shows the location of the Sun and several constellations at noon on a particular day. (On this day, the Sun is in Gemini.) Which constellation will the Sun mostly likely be in one month later? ("East" is to the left in this image, "West" is to the right.)
leo
cancer
gemini
taurus
aries
Which of the following observations are consistent with the Geocentric Model (shown below)? (Check all that apply; assume all observations are made from Earth)
Jupiter, Saturn, and Mars sometimes show retrograde motion
The Moon shows retrograde motion once a month
Stars do not show parallax
Mercury and Venus can never be found opposite the Sun in the sky
If you're observing from High Point, NC, which month will the full moon be highest in the sky at midnight? (Hint: the moon generally follows the ecliptic; think of the tilt of the ecliptic and where the moon is with respect to the Sun)
December
March
September
June
If you're observing from High Point, NC, which month during the year will the Sun be the highest in the sky at NOON?
June
March
December
September
The image below illustrates the observations made by Eratosthenes in order to estimate the size of the Earth. If he measures an angle of for the shadow cast by a pole in Alexandria when a pole in Syene casts no shadow at all, and if he measures a distance of between Alexandria and Syene, what would he calculate for the circumference of Earth in stadia? (Choose the closest answer below; you can work this without a calculator.)
36 stadia
360 stadia
120,000 stadia
12,000 stadia
How did Aristotle deduce that the Sun is farther away from Earth than the Moon?
He noticed during solar eclipses that the Moon passes in front of the Sun, and the opposite case never happens
He noticed that we can see features on the surface of the Moon, but not on the Sun.
He saw that the Moon moves more quickly against the background stars, and therefore must be closer.
He noticed that the Sun and Moon appear to be the same size in the sky, even though the Sun is actually much bigger.
What are two ways in which Aristotle deduced that Earth is spherical?
The Moon casts a circular shadow during a solar eclipse
The Moon displays crescent and gibbous phases.
The Earth casts a circular shadow on the Moon during a lunar eclipse
As travelers go further south, they see more total stars and fewer circumpolar stars.
Venus displays phases like the Moon.
Why did Ptolemy have to introduce multiple circles of motion for the planets instead of a single, simple circle to represent the planet's motion around the Sun?
Ptolemy had to account for the occasional retrograde motion of the planets, which was unexpected in a geocentric system.Ptolemy had to account for the precession of the Earth's axis.
Ptolemy had to account for the precession of the Earth's axis.
Ptolemy had to account for the stellar parallax he observed, which was unexpected since he believed the Earth to be stationary
Ptolemy had to account for small differences between the expected positions of the planets and their observed positions, caused by the fact that planetary orbits are actually ellipses.
During a retrograde loop of Mars, would you expect Mars to be brighter than usual in the sky, about average in brightness, or fainter than usual in the sky?
brighter than usual
about average brightness
fainter than usual
The picture below shows the incident angle of the Sun's rays on the Earth at a particular time of year. Which season would South America be experiencing in this moment?
Fall
Impossible to tell
Summer
Winter
Spring
Which of the following hypotheses is more 'scientific' in nature? (Use the definition of scientific hypotheses discussed in class.)
These are microbes living under a rock at the North pole of Mars.
There is microbial elsewhere in the universe.
In the heliocentric model (shown below), if you were observing the stars and planets FROM THE SURFACE OF MARS, which of the following planets could NEVER be found opposite the Sun in the Martian sky? (Check all that apply)
Mercury
Saturn
Earth
Jupiter
If one took a picture of the Sun at NOON approximately once per week for 1 year (same location, same time of day, same orientation each picture), a stack of all these images would look like the image below. In addition to telling you the Sun's North-South position changes throughout the year (which gives rise to the seasons), what else does this pattern tell you?
The sun never sets at this location on the earth
The moon will take ~27 days to circle the ecliptic
The sun's speed around the ecliptic varies throughout the year
You have just discovered a new planet (named "Planet-2018") in our own Solar System. Assume it has a circular orbit around the Sun. If you determine the orbital separation distance between the Sun and Planet-2018 to be 4 AU, what should you measure for its orbital period?(Hint: use the form of Kepler's Third Law where the units are AU and years)
4years
64years
8years
.5years
16years
In the distant future, the earth will rotate more slowly and the moon will be farther away. Suppose a future citizen of Earth measures the distance to the moon to be 3 times farther away than it is now. Approximately how long will its orbital period be compared to its period now? (Choose the BEST answer from the choices below; first decide whether the period will be longer or shorter)
9 times shorter
no change
3 times shorter
27 times longer
5 times longer
Tycho Brahe preferred a hybrid model of the solar system (shown below) in which the Sun and Moon orbit the Earth, but all the other planets orbit the Sun. What does this model predict for the phases of Venus, as viewed from Earth?
Venus should show all possible phases, except a full phase.
Venus will not show changing phases.
Venus should show all possible phases, just like the moon.
Venus is not visible from Earth in this model.
The diagram below illustrates the orbit of a planet revolving around the Sun in an ellipse. The Sun is the dark shaded circle at one focus of the ellipse. If the planet takes the same amount of time to travel between points A & B as it does to travel between points C & D, how must the area of the shaded region "1" compare to the area of shaded region "2"?
The area of region 1 is larger.
The area of region 2 is larger.
Both regions have the same area.
Which of the following observations (all of which are true) actually FALSIFIES the geocentric model of the universe (shown below)?
The sun takes approximately 365 days to circle the ecliptic.
Mercury and Venus are always found close to the Sun in the sky.
Venus goes through new, quarter, and full phases - just like the moon.
Planets generally move Eastward with respect to the stars, but occasionally move Westward.
Of the following locations, where could Mercury and Venus be found in our sky?
90 degrees away from the Sun.
next to a full moon.
5 degrees away from the Sun.
opposite the Sun.
TRUE or FALSE: Both the geocentric and heliocentric models of the universe can explain retrograde motion.
true
false
What prediction do both the geocentric and heliocentric models make about the outer planets (Mars, Jupiter, Saturn) while they're in retrograde motion?
They should be a little fainter
They should disappear from view for a few weeks
they should be a little brighter
they are too close to the sun to see then
The human body radiates energy like a blackbody (a thermal, opaque source) with a peak wavelength in the infrared near 10,000 nm ["nanometers"]. Even though we're all emitting light, we cannot see people glowing because our eyes are only sensitive to optical wavelengths in the range 380-750 nm. Assuming you can run as fast as you'd like, how fast would you have to run towards another human to see him/her "glowing" bluish-green with your own eyes, at a peak wavelength of 500 nm? (Choose best answer; answers given in terms of the speed of light, c.)
0.75c (75% the speed of light)
0.05c (5% the speed of light)
0.95c (95% the speed of light)
20c (20 times the speed of light)
Of the four atoms shown below, which atom is absorbing the bluest photon?
Atom A
Atom B
Atom C
Atom d
The top part of the picture below shows an emission line spectrum of Hydrogen. The bottom panel shows the electron orbital levels in a Hydrogen atom, with 4 red arrows showing the electron transitions that give rise to the 4 emission lines seen in the spectrum above. Which electron orbital level transition (A,B,C,D) is responsible for emitting the green line in the spectrum (the emission line circled and marked with a question mark)?
Transition A
Transition B
Transition C
Transition D
Which of the following statements accurately describe our Solar System? (Check all that apply.)
All of the planets orbit the Sun in the same direction.
The orbits of the planets are all approximately in the same plane.
Small rocky planets are close to the Sun, large gaseous planets are farther away from the Sun.
Most of the mass is in the Sun.
Different planets orbit the Sun in different directions (some clockwise, others counter-clockwise).
After taking a spectrum of your favorite star, you notice it has an absorption line due to Hydrogen at 451 nm. If the rest-frame (non-moving) wavelength of this Hydrogen line is supposed to be 410 nm, what is the approximate radial velocity of this star in kilometers per second (km/s)? Choose the best answer. (Assume for simplicity that the speed of light 'c' is 300,000 km/s)
0.1 km/s away from you
41 km/s away from you
30,000 km/s away from you
27,272 km/s away from you
Rank the following types of electromagnetic radiation according to their relative energies. Use a scale of decreasing energy from 1 to 6, where "1" corresponds to the most energetic form of light and "6" corresponds to the least energetic type of light.
Infrared
UltraViolet (UV) radiation
x-rays
gamma rays
radio waves
optical (visible) light
(a)
The figure below shows the spectra of two stars on the same scale (Star A = red line; Star B = green line). The three strongest (deepest) absorption lines in each spectrum are due to the same element (they are marked with arrows in the Star A spectrum). How does the radial velocity of Star B compare to the radial velocity of Star A? (Choose the most correct answer; assume both spectra were taken from Earth.)
Star A and Star B are both moving away from the Earth with the same radial velocity.
Star A and Star B are both moving towards the Earth with the same radial velocity.
Star B is moving away from the Earth faster than Star A.
Star B is moving towards the Earth faster than Star A.
In order for an object to be officially classified as a "planet", which of the following criteria must be met? (assume the IAU's definition of planet; check all that apply)
must have cleared its neighborhood of debris (around its orbit)
must orbit the Sun
must have sufficient mass to have a nearly round shape
must have an atmosphere
The figure below shows the thermal spectra of four different stars (Star A, Star B, Star C, Star D). Which star has the highest effective temperature?
Star A
Star B
Star C
Star D
The top panel in the figure below shows the optical spectrum for a star. The bottom four panels show emission line spectra corresponding to four different elements. According to the star's spectrum, which of these elements can be found in the star's atmosphere? (Choose all that apply; assume none of the spectra are redshifted or blueshifted).
Element A
Element B
Element C
Element D
what spectrum is this?
contuniuum
emission
absorption
what spectrum is this?
continuum
emission
absorption
what spectrum is this?
continuum
emission
absorption
Gamma-ray photons are much more energetic than infrared photons. How do their velocities compare to one another?
Infrared photons travel faster than gamma-rays.
Gamma-rays travel faster than infrared photons.
Gamma-rays and infrared photons travel at the same speed.
Which of the following atoms is/are emitting light?
Atom A
Atom b
atom a and c
atom b and d
Which type of light has the longer wavelength?
blue
red
Which of the following is NOT one of the three types of spectra (according to Kirchoff's Laws)?
absorption
emission
continuum
electric
Star A and Star B have IDENTICAL COLORS, but Star A has a HIGHER LUMINOSITY than Star B does. How is this possible?
Star A must be bigger (larger radius).
this is impossible
star a must be closer to earth
Do stars exist in the universe with light output peaking at a GREEN wavelength?
no, there are no stars at that peak in the green
yes, but the human eye detects them as white
A red star and a blue star have the same radius. Which star will have a higher luminosity?
The red star will have higher luminosity.
They will both have the same luminosity.
The blue star will have higher luminosity.
Two people are observing the Sun. One is standing on Pluto while the other is standing on Earth. Will they agree on the Sun's LUMINOSITY?
Yes - the Sun has the same luminosity for both observers.
No - the Earth observer will find a higher luminosity for the Sun.
No - the Pluto observer will find a higher luminosity for the Sun.
Two stars appear to be equally bright to your eyes in the sky, but you know one of the stars is actually much farther away than the other. How is this possible?
The farther away star must have a higher luminosity in order to look equally bright.
The farther away star must have a lower luminosity in order to look equally bright.
This is impossible.
Star A is 10 light-years away, and Star B is 100 light-years away. Which star will show the BIGGER parallax shift in its position?
Star A will show the bigger parallax
Star B will show the bigger parallax
Star X shows a parallax angle 2 times larger than that of Star Y. If the observed flux (apparent brightness) for Star X is 8 times larger (brighter) than the observed flux for Star Y, how do their luminosities compare?
Star Y's luminosity is 4 times greater than Star X's
Star X's luminosity is 2 times greater than Star Y's
Star X's luminosity is 4 times greater than Star Y's
Star Y's luminosity is 2 times greater than Star X's
Transit light curves are shown below for two different exo-planetary systems. Assuming both planets are orbiting stars of the same size, which of the two planets is smaller? (also assume the light curves below are plotted using the same scale)
Planet in System B
Planet in System A
Order the following systems according to how easy they are to detect using the radial velocity method, starting with the easiest (top) and ending with the most difficult (bottom). (Assume the stars are identical in all three cases)
(a)
The figure below illustrates parallax for a nearby star, as measured from Earth. If the Earth's orbit were larger than it is now (increase in size), what would happen to the parallax measured for nearby stars? (assume the stars have not changed their physical positions in the Galaxy.)
stars would show larger parallax angles
stars would show smaller parallax angles
parallax measurements would not change (not affected by size of Earth's orbit)
A star can be thought of as a hot, opaque thermal source (its core) surrounded by a layer of cooler gas (its atmosphere). Given this description, which of the spectra best matches what you would expect for a star?
continuum
emission
absorption
If the star Vega were suddenly moved 4 times farther away, what would happen to its flux, as observed from Earth?
increases by a factor of 4
decreases by a factor of 4
increases by a factor of 16
decreases by a factor of 16
You discover a nearby star with a parallax of 0.25 arcseconds. How far away is it? (assume parallax measured from Earth)
0.25 parsec
4 parsec
0.50 parsec
2 parsec
The figure below shows the light curve (brightness vs. time) for a star with an orbiting exoplanet (real astronomical data!). What is the approximate orbital period of the planet?
1 day
3 days
6 days
15 days
Star A and Star B have identical luminosities. If you observe Star A's flux to be greater than (brighter than) Star B's flux, which of this following is true? (choose best answer; assume observing from Earth)
Star A and Star B are at equal distances
Star A is closer to Earth than Star B
Star B is closer to Earth than Star A
The question makes no sense because they must have the same flux since they have the same luminosity.
TRUE or FALSE: All systems of planets discovered around other stars look identical to our Solar System.
true
false
If the star Vega were suddenly moved 3 times closer to Earth, what would happen to its luminosity?
increases by a factor of 27
decreases by a factor of 27
increases by a factor of 3
decreases by a factor of 3
it does not change
Star A and Star B have identical temperatures and are plotted in the H-R diagram shown below. Which star is smaller?
Star A is smaller
Star B is smaller
Not enough information to answer
They are both the same size
The figure below shows and H-R diagram populated with nearby stars. What might you call stars falling within the circled region? (Choose the most sensible name, regardless of whether it sounds like a formal, scientific classification)
Red giants
Blue dwarfs
Red dwarfs
Blue supergiants
You randomly notice two stars in the night sky with the same apparent brightness (flux). One star looks red while the other star looks bluish-white. Using only the information given, which star has the higher luminosity? (Choose the best answer; don't assume the stars are both main sequence stars--you don't have that information)
The red star is more luminous
Not enough information to answer
Both have the same luminosity
The blue star is more luminous
Which of the following best describes how the overall optical color of a globular cluster changes as it evolves, if you could watch it from the time when all of its stars are born to the time when most of its stars have 'died'? (Choose the best answer; assume the cluster starts off with main sequence stars of all allowable masses/temperatures.)
The color changes from blue to red
The color doesn't change
The color changes from red to blue
How does the luminosity of a main sequence star with a mass of 2 Msun compare to the luminosity of the sun? (Choose the closest answer; use the mass-luminosity relationship from class)
Higher by a factor of 11
Higher by a factor of 3.5
Lower by a factor of 2
Lower by a factor of 11
The H-R diagram below plots all of the stars closest to Earth, along with four additional main sequence stars (Stars A, B, C, D). Which star uses up its available hydrogen fuel the least quickly? (Choose best answer)
Star A
Star B
Star C
Star D
Which of the following most accurately describes what 'powers' the Sun? (Choose the most correct answer)
The core of the Sun is converting hydrogen to helium through nuclear fusion; some of the original mass is 'lost' along the way and converted to energy through E=mc^2. A lot of this energy is emitted in the form of light.
The Sun gives off light because it is on fire; it gives off smoke and leaves behind charcoal, just like a candle or campfire does (but on a much bigger scale)
The Sun is constantly gravitationally collapsing (decreasing in radius). As it does, its temperature and pressure increase, and energy is emitted in the form of light. As energy is released, however, the temperature decreases, and so it has to continually contract in order to emit energy at a constant level.
If all of the stars listed below are currently fusing hydrogen on the main sequence, which has the highest luminosity? (Choose the best answer; the colors describe how the stars would appear to the human eye, assuming perfect vision)
A yellow-white star
A red star
An orange star
A blue star
You are studying a binary star system and find its total mass to be 6 Msun. If one star has an orbital velocity of 10 km/s and the other star a velocity of 20 km/s, what are the masses of the two stars? (1 Msun = 1 solar mass)
3 Msun and 3 Msun
2 Msun and 4 Msun
6 Msun and 12 Msun
1 Msun and 5 Msun
Star X and Star Y orbit one another and represent a stellar binary. If Star X orbits with a speed of 90 km/s, and Star Y orbits with a speed of 30 km/s, which star is more massive and by how much? (Choose best answer)
Star Y is 3 times more massive
Star X is 9 times more massive
Star Y is 9 times more massive
Star X is 3 times more massive
You are observing a binary star system with an orbital period of 2 years. If the two stars are separated by a distance of 2 AU, what is the total mass of the system? (Give answer in units of solar mass, )
.5M
15M
4M
2M
The figure below shows and H-R diagram populated with nearby stars. What might you call stars falling within the circled region? (Choose the most sensible name, regardless of whether it sounds like a formal, scientific classification)
Red dwarf
red giant
blue dwarf
blue gians
Star A and Star B have identical temperatures and are plotted in the H-R diagram shown below. Which star is smaller?
Star A is smaller
Not enough information to answer
They are both the same size
Star B is smaller
You randomly notice two stars in the night sky with the same apparent brightness (flux). One star looks red while the other star looks bluish-white. Using only the information given, which star has the higher luminosity? (Choose the best answer; don't assume the stars are both main sequence stars--you don't have that information)
The red star is more luminous
Both have the same luminosity
The blue star is more luminous
Not enough information to answer
Classify the galaxies below.
irregular
spiral
elliptical
Classify the galaxies below.
irregular
spiral
elliptical
Classify the galaxies below.
irregular
spiral
elliptical
A collision between the two galaxies shown below is likely to produce which type of galaxy? (Can click on the galaxy image itself to mark.)
irregular
spiral
elliptical
Cepheid A and Cepheid B both have the same apparent brightness (flux), but you know from parallax measurements that Cepheid A is much closer. Which star should have a longer pulsational period? (As a reference, the period-luminosity relation for Cepheids is included below.)
Cepheid B
Cepheid A
They both have the same pulsational period
Not enough information to answer.
If all of the white dwarfs listed below have the same temperature, which will have the highest luminosity? (Choose best answer)
a white dwarf with mass 0.5 Msun
a white dwarf with mass 1.0 Msun
a white dwarf with mass 1.3 Msun
they will all have the same luminosity
Which of the following best describes what keeps a white dwarf from gravitationally collapsing? (Choose the best answer).
The electrons repel one another since they all have the same electrical charge (negative). The combined electric force of all the electrons supports the star against gravitational collapse.
The star is degenerate--the electrons are so tightly packed that they occupy all possible quantum states. To compress them further would violate the Pauli Exclusion Principle.
Internal nuclear fusion of carbon and oxygen provide an outward force of pressure
Which of the stars below has the hottest core temperature? (Choose best answer)
a star fusing hydrogen to helium in its core
a star fusing carbon to oxygen, neon, sodium and magnesium in its core
a star fusing helium to carbon in its core
What would stars be like if Hydrogen (instead of Iron) had the smallest mass per nucleon and the strongest nuclear binding energy of all the elements? (Choose the best answer)
Nuclear fusion would not occur in stars
Stars would be brighter on average
All stars would be red supergiants
Stars would live much longer on the main sequence
In which type of galaxy would you least expect to find a lot of O-type and B-type main sequence stars?
Elliptical Galaxy
Spiral Galaxy
When a star like the Sun evolves into a red giant, what happens to its core? (Choose best answerd)
it contracts and heats up
it expands and cools
it turns into carbon
it expands and heats up
Which of the sequences below most accurately describes the evolution of the Sun? (Choose best answer; age increases from left to right)
Protostar --> Main Sequence --> Red Giant --> Planetary Nebula --> White Dwarf
Protostar --> White Dwarf --> Main Sequence --> Red Giant --> Supernova --> Neutron Star
Protostar --> Main Sequence --> Planetary Nebula --> Red Giant --> White Dwarf
Protostar --> Main Sequence --> Red Giant --> Planetary Nebula --> White Dwarf --> Neutron Star --> Black Hole
You discover a star with spectral type A. If the width of absorption features in its spectrum indicates it has a luminosity class of V, what is its luminosity? (Choose the closest answer)
50 L
500 L
.01L
12;
A planetary nebula is most accurately described as
a shell of gas ejected from a star late in its life.
the disk of gas around a young star.
what is left when a white dwarf explodes as a supernova.
a cloud of gas surrounding a planet that forms from volcanic activity.
TRUE OR FALSE: You can see some planets (other than Earth) with your naked eye, without the use of binoculars/telescopes.
true
false
In which direction do the planets -usually- appear to move with respect to the background stars?
North
South
West
East
TRUE OR FALSE: The stars always set at the same angle everywhere on Earth.
true
false
How long do the stars take to complete a full circle across the sky?
less than 24 hours
more than 24 hours
approximately 24 hours
Which most accurately describes our solar system?
All of the planets orbit the Sun in perfect circles.
All of the planets and the Sun orbit the Earth.
All of the planets orbit the Sun in ellipses.
TRUE or FALSE: Both models (heliocentric & geocentric) can explain retrograde motion of the planets.
true
false
What's the actual cause of seasons on Earth?
Earth's axis is tilted by 23.5 degrees.
Earth's orbit is an ellipse, not a circle.
Earth is closer to the Sun in the summer, farther away from the Sun in the winter.
What do astronauts experience 'weightlessness' in the International Space station?
There's no gravity in space.
They're in constant free-fall (similar to a skydiver).
Earth's gravity does not reach out that far or is too weak at that distance.
What phase should Venus NEVER show in the geocentric model?
Third Quarter
First Quarter
Full
new
How many planets are there in our solar system?
Fifteen (15)
Nine (9)
Eight (8)
Ten (10)
What do you call an object that only meets TWO of the three criteria for being called a "planet"?
asteroid
dwarf planet
meteor
comet
Is Pluto a "planet"?
yes
no
If I am moving AWAY from an object -very- quickly, what will be true about the color I observe for it compared to its true (i.e., at rest) color?
I will observe a color with SHORTER wavelength than its true color.
I will observe the same color it would be were I at rest.
I will observe a color with LONGER wavelength than its true color.
TRUE or FALSE: Gamma rays, X-rays, optical light, & infrared rays are all different forms of the same thing: light.
true
false
TRUE or FALSE: We can tell what elements stars are made of halfway across the universe, without ever going there and collecting samples.
true
false
Which of the atoms below is EMITTING light? (Note the nucleus is shown in green, the electron orbital levels in black circles, the electron in red, and the path of the electron jump with a black arrow.)
Atom A is emitting light.
Atom B is emitting light.
Both Atom A and Atom B are emitting light.
almost everything we know about the universe comes from ...
telescopes
light
mass
ideas
What are the only directly measurable quantities in astronomy?
time
polorization
color
brightness
Which planets are generally the easiest to find using the radial velocity method?
high-mass planets close to their host stars
low-mass planets close to their host stars
high-mass planets far away from their host stars
low-mass planets far away from their host stars
Which planets are generally the easiest to find using the transit method?
smaller planets close to their host stars
smaller planets far away from their host stars
larger planets close to their host stars
larger planets far away from their host stars
Which planets are generally the easiest to find using the transit method?
terrestrial planets
gaseous planets
Star A and Star D are the same size. If Star A is a red star and Star D is a blue star, which is more luminous?
star A
Star D
Star A and Star D are the same size. If Star A is 2 times hotter than Star D how many times more luminous is Star A?
2 times
4 times
16 times
34 times
The radius of a star can be determined from what?
spectral type
temperature
luminosity
is Terrestrial (rocky) close to Sun
yes
no
Is Jovian (gaseous) planets close to Sun
yes
no
More massive star has a higher velocity
true
false
In example #1, we found the total mass of a binary system with a period of 4 years and a separation of 2 AU to be 0.5 Msun. From spectroscopy, you find the velocity of one star to be 4 times the velocity of the other. What are the individual stellar masses?
0.25 & 0.25 Msun
0.2 & 0.8 Msun
0.4 & 0.1 Msun
2 & 8 Msun
What is the total mass of a binary system with a period of 4 years and a separation of 2 AU?
0.50 Msun
.66 Msun
2Msun
16Msun
Two stars orbit each other once every 3 years and are separated by 3 AU. If one star orbits 2 times faster than the other, what are their masses?
0.11 & 0.22 Msun
0.5 & 1.5 Msun
1 & 2 Msun
3 & 6 Msun
Which stars are most massive?
red main sequence stars
yellow main sequence stars
blue main sequence stars
white main sequence stars
Low-mass stars have the longest main sequence lifetimes.
T
F
High-mass stars have the longest main sequence lifetimes.
T
F
