Question 1

The three stars of the Summer Triangle are

Accepted Answer

A) Antares,Arcturus,and Spica. 
B) Arcturus,Vega,and Algol. 
C) Deneb,Spica,and Vega. 
D) Vega,Deneb,and Altair. 
E) Altair,Antares,and Arcturus. 
A) Antares,Arcturus,and Spica. 
B) Arcturus,Vega,and Algol. 
C) Deneb,Spica,and Vega. 
D) Vega,Deneb,and Altair. 
E) Altair,Antares,and Arcturus. D

Question 2

The lunar month is longer than the sidereal month because

Accepted Answer

A) the Moon completes the cycle of lunar phases before it completes a full orbit around Earth. 
B) the Moon has to complete more than one full orbit around Earth to complete the cycle of lunar phases. 
C) the Moon orbits Earth faster than Earth orbits the Sun. 
D) the Moon orbits Earth faster than Earth rotates. 
E) the lunar month is based on the Moon's orbit,while the sidereal month is based on Earth's orbit. 
A) the Moon completes the cycle of lunar phases before it completes a full orbit around Earth. 
B) the Moon has to complete more than one full orbit around Earth to complete the cycle of lunar phases. 
C) the Moon orbits Earth faster than Earth orbits the Sun. 
D) the Moon orbits Earth faster than Earth rotates. 
E) the lunar month is based on the Moon's orbit,while the sidereal month is based on Earth's orbit. B

Question 3

Your Local Sky
a.Where is the north (or south)celestial pole in your sky?
b.Describe the meridian in your sky.
c.Describe the celestial equator in your sky.
d.What is the range of declinations that makes a star circumpolar in your sky? Explain.
e.Describe the path of the Sun through your sky on the fall equinox.
f.Describe the path of the Sun through your sky on the winter solstice.

Accepted Answer

Answers will vary with latitude;the following is a sample answer for latitude 40°N.
a.The north celestial pole appears in the sky at an altitude of 40°,in the direction due north.
b.The meridian is a half-circle that stretches from the point due south on the horizon,through the zenith,to the point due north on the horizon.
c.The celestial equator is a half-circle that stretches from the point due east on the horizon,through an altitude of 50° due south,to the point due west on the horizon.
d.Because the north celestial pole appears due north at an altitude of 40°,a star is circumpolar if it is within 40° of the north celestial pole.The north celestial pole has a declination of +90°,so within 40° means declinations greater than +50°.
e.On the fall equinox,the Sun rises due east,reaches an altitude of 50°S on the meridian,and sets due west.
f.On the winter solstice,the Sun rises more than 23.5° south of due east,reaches an altitude of 50° - 23.5° = 26.5° on the meridian in the south,and sets more than 23.5° south of due west.

Question 4

Choose the appropriate star from Table S1.2 for the following questions:
Table S1.2
  
-Which star remains above the horizon for the longest time each day at latitude 40°N?

Accepted Answer

The answer of Choose the appropriate star from Table S1.2...

Question 5

Which of the following is the reason for the solar day being longer than a sidereal day?

Accepted Answer

A) precession of Earth's axis 
B) the tilt of Earth's axis 
C) the combined effect of the rotation of Earth and its orbit about the Sun 
D) Earth year being a non-integer number of Earth days 
E) the non-circular orbit of Earth around the Sun 
A) precession of Earth's axis 
B) the tilt of Earth's axis 
C) the combined effect of the rotation of Earth and its orbit about the Sun 
D) Earth year being a non-integer number of Earth days 
E) the non-circular orbit of Earth around the Sun

Question 6

The amount of time between successive passes of any given star across the meridian is

Accepted Answer

A) 23 hours 56 minutes. 
B) 24 hours. 
C) 365.25 days. 
D) 12 years. 
E) 26,000 years. 
A) 23 hours 56 minutes. 
B) 24 hours. 
C) 365.25 days. 
D) 12 years. 
E) 26,000 years.

Question 7

Suppose you live at the North Pole.Describe the path of the Sun through your sky for each of the following days:
a.the day of the spring equinox
b.the day of the summer solstice
c.the day of the winter solstice

Accepted Answer

a.On the vernal equinox,the Sun circles

Question 8

The Sun's declination on June 21st is

Accepted Answer

A) +23.5 degrees. 
B) 0 degrees. 
C) -23.5 degrees. 
D) different depending on where you are on Earth. 
A) +23.5 degrees. 
B) 0 degrees. 
C) -23.5 degrees. 
D) different depending on where you are on Earth.

Question 9

What kind of time can be read directly from a sundial?

Accepted Answer

A) apparent solar time 
B) mean solar time 
C) standard time 
D) universal time 
A) apparent solar time 
B) mean solar time 
C) standard time 
D) universal time

Question 10

Suppose you have a time-keeping device that always reads precisely 12:00 when the Sun crosses your meridian.What kind of time is this clock keeping?

Accepted Answer

A) mean solar time 
B) standard time 
C) apparent solar time 
D) universal time 
A) mean solar time 
B) standard time 
C) apparent solar time 
D) universal time

Question 11

Note to instructors: The following question assumes you gave a "lost at sea" question on your midterm.

Accepted Answer

It is often said that history repeats it

Question 12

Choose the appropriate star from Table S1.1 for the following questions:
Table S1.1
  
-Which star lies closest to the celestial equator on the celestial sphere?

Accepted Answer

The answer of Choose the appropriate star from Table S1.1...

Question 13

For the following questions,refer to Figure S1.2,which shows a portion of the sky visible in the early evenings in winter.Note that five bright stars are labeled with lowercase letters and five constellations are labeled with capitals.A few hints are also given.
  
-Which constellation (capital letters)is Orion?

Accepted Answer

The answer of For the following questions,refer to Figure S1.2,which...

Question 14

The three bright stars that make up the Winter Triangle are

Accepted Answer

A) Polaris,Aldebaran,and Algol. 
B) Polaris,Betelgeuse,and Sirius. 
C) Betelgeuse,Procyon,and Sirius. 
D) Betelgeuse,Rigel,and Aldebaran. 
E) Capella,Procyon,and Sirius. 
A) Polaris,Aldebaran,and Algol. 
B) Polaris,Betelgeuse,and Sirius. 
C) Betelgeuse,Procyon,and Sirius. 
D) Betelgeuse,Rigel,and Aldebaran. 
E) Capella,Procyon,and Sirius.

Question 15

Suppose it is January and the Sun remains above your horizon all day long.Where must you be located?

Accepted Answer

A) at the South Pole 
B) at the North Pole 
C) somewhere between the Antarctic Circle and the South Pole 
D) somewhere between the Arctic Circle and the North Pole 
A) at the South Pole 
B) at the North Pole 
C) somewhere between the Antarctic Circle and the South Pole 
D) somewhere between the Arctic Circle and the North Pole

Question 16

The average length of a solar day is

Accepted Answer

A) 23 hours 56 minutes. 
B) 24 hours. 
C) 365.25 days. 
D) 12 years. 
E) 26,000 years. 
A) 23 hours 56 minutes. 
B) 24 hours. 
C) 365.25 days. 
D) 12 years. 
E) 26,000 years.

Question 17

All the following statements are true.Which one explains why our calendar has leap years?

Accepted Answer

A) Earth's axis precesses with a period of about 26,000 years. 
B) There is a difference between a sidereal year and a tropical year. 
C) A tropical year is slightly more than 365 days. 
D) Earth's speed varies as it orbits the Sun. 
A) Earth's axis precesses with a period of about 26,000 years. 
B) There is a difference between a sidereal year and a tropical year. 
C) A tropical year is slightly more than 365 days. 
D) Earth's speed varies as it orbits the Sun.

Question 18

Each of the following lists a constellation and a bright star.In all cases but one,the star is part of the constellation.Which one is the mismatch?

Accepted Answer

A) Scorpio,Vega 
B) Cygnus,Deneb 
C) Boötes,Arcturus 
D) Virgo,Spica 
E) Auriga,Capella 
A) Scorpio,Vega 
B) Cygnus,Deneb 
C) Boötes,Arcturus 
D) Virgo,Spica 
E) Auriga,Capella

Question 19

For the following questions,refer to Figure S1.2 which shows a portion of the sky visible in the early evenings in winter.Note that five bright stars are labeled with lowercase letters and five constellations are labeled with capitals.A few hints are also given.
  
-Which constellation (capital letters)is Canis Minor?

Accepted Answer

The answer of For the following questions,refer to Figure S1.2...

Question 20

For the following questions,refer to Figure S1.1,which shows a portion of the sky visible in the early evenings in the fall.Note that five bright stars are labeled with lowercase letters and five constellations are labeled with capitals.A few hints are also given.
  
-Which constellation (capital letters)is Perseus?

Accepted Answer

The answer of For the following questions,refer to Figure S1.1,which...

Exam 25: Celestial Timekeeping and Navigation

The three stars of the Summer Triangle are

The lunar month is longer than the sidereal month because

Choose the appropriate star from Table S1.2 for the following questions: Table S1.2 -Which star remains above the horizon for the longest time each day at latitude 40°N?

Which of the following is the reason for the solar day being longer than a sidereal day?

The amount of time between successive passes of any given star across the meridian is

Suppose you live at the North Pole.Describe the path of the Sun through your sky for each of the following days: a.the day of the spring equinox b.the day of the summer solstice c.the day of the winter solstice

The Sun's declination on June 21st is

What kind of time can be read directly from a sundial?

Suppose you have a time-keeping device that always reads precisely 12:00 when the Sun crosses your meridian.What kind of time is this clock keeping?

Note to instructors: The following question assumes you gave a "lost at sea" question on your midterm.

Choose the appropriate star from Table S1.1 for the following questions: Table S1.1 -Which star lies closest to the celestial equator on the celestial sphere?

The three bright stars that make up the Winter Triangle are

Suppose it is January and the Sun remains above your horizon all day long.Where must you be located?

The average length of a solar day is

All the following statements are true.Which one explains why our calendar has leap years?

Each of the following lists a constellation and a bright star.In all cases but one,the star is part of the constellation.Which one is the mismatch?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light and Matter: Reading Messages from the Cosmos

Telescopes: Portals of Discovery

Our Planetary System

Formation of the Solar System

Planetary Geology: Earth and the Other Terrestrial Worlds

Planetary Atmospheres: Earth and the Other Terrestrial Worlds

Jovian Planet Systems

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: The New Science of Distant Worlds

Our Star

Surveying the Stars

Star Birth

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundations of Modern Cosmology

Galaxy Evolution

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Space and Time

Spacetime and Gravity

Building Blocks of the Universe

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