Question 1

Which of the following are most massive and luminous?

Accepted Answer

A) brown dwarfs 
B) RR Lyrae variables 
C) white dwarfs 
D) T Tauri variables 
E) Cepheid variables 
A) brown dwarfs 
B) RR Lyrae variables 
C) white dwarfs 
D) T Tauri variables 
E) Cepheid variables

Question 2

All RR Lyrae stars have about the same:

Accepted Answer

A) period of six hours. 
B) distance of 32 light-years. 
C) galactic location and speed. 
D) luminosity of about 100 Suns. 
E) locations in the centers of globular star clusters. 
A) period of six hours. 
B) distance of 32 light-years. 
C) galactic location and speed. 
D) luminosity of about 100 Suns. 
E) locations in the centers of globular star clusters.

Question 3

Who discovered the period-luminosity relationship, and why was it so critical?

Accepted Answer

Henrietta Leavitt discovered the period-

Question 4

Henrietta Leavitt first showed the relationship between the mass and luminosity of Cepheidsand their period of pulsation; the brighter, the longer this period.

Accepted Answer

A) True 
 B)False

Question 5

The core of the Milky Way, Sagittarius A, is a strong radio source in the sky.

Accepted Answer

A) True 
 B)False

Question 6

Low mass white dwarfs could account for how much of the dark matter in our Galactic halo?

Accepted Answer

A) up to 20% 
B) at least 50% 
C) all of it 
D) no more than 1% 
E) none 
A) up to 20% 
B) at least 50% 
C) all of it 
D) no more than 1% 
E) none

Question 7

Which of these is NOT typical of the Galaxy's spiral arms?

Accepted Answer

A) hot, young blue Population I stars 
B) emission nebulae like M42 
C) O and B stars 
D) open clusters 
E) Population II giants like orange Arcturus 
A) hot, young blue Population I stars 
B) emission nebulae like M42 
C) O and B stars 
D) open clusters 
E) Population II giants like orange Arcturus

Question 8

Harlow Shapley found the Milky Way was:

Accepted Answer

A) centered on the Earth. 
B) much smaller than previously thought. 
C) rapidly expanding. 
D) much larger than previously thought. 
E) uniformly spherical in shape. 
A) centered on the Earth. 
B) much smaller than previously thought. 
C) rapidly expanding. 
D) much larger than previously thought. 
E) uniformly spherical in shape.

Question 9

Who was Henrietta Leavitt, and what did she do to help map the universe?

Accepted Answer

This Harvard astronomer found the period

Question 10

What observations suggest the mass of the Galaxy goes much farther out than its visibledisk?

Accepted Answer

A) 21 cm maps of the spiral arms 
B) the rotation curve of the outermost portions of the disk 
C) the orbits of the open clusters in the disk 
D) infrared observations of distant brown dwarfs 
E) X-ray images of other galaxies' disks from Chandra 
A) 21 cm maps of the spiral arms 
B) the rotation curve of the outermost portions of the disk 
C) the orbits of the open clusters in the disk 
D) infrared observations of distant brown dwarfs 
E) X-ray images of other galaxies' disks from Chandra

Question 11

S2's orbital radius of 950 A.U. and an orbital period of 15 years are most consistent with S2being a star:

Accepted Answer

A) passing within a light-year of our solar system. 
B) orbiting a 4 million solar mass object in the center of our Galaxy. 
C) with a mass 4 million times the mass of our Sun. 
D) in a globular cluster that has a mass about 4 million times the mass of our Sun. 
E) being sucked into the black hole in the center of our Galaxy. 
A) passing within a light-year of our solar system. 
B) orbiting a 4 million solar mass object in the center of our Galaxy. 
C) with a mass 4 million times the mass of our Sun. 
D) in a globular cluster that has a mass about 4 million times the mass of our Sun. 
E) being sucked into the black hole in the center of our Galaxy.

Question 12

From the center of the Milky Way, 10- kpc-long magnetized jets of high-energy particles areemitted.

Accepted Answer

A) True 
 B)False

Question 13

Most of the new star formation in the Galaxy is found in the:

Accepted Answer

A) Galactic halo. 
B) spiral arms. 
C) Galactic bulge. 
D) Galactic center. 
E) Globular clusters. 
A) Galactic halo. 
B) spiral arms. 
C) Galactic bulge. 
D) Galactic center. 
E) Globular clusters.

Question 14

How does metal content vary between Population I and II? Why?

Accepted Answer

Older Population II stars are made of al

Question 15

What two observations allow us to calculate the Galaxy's mass?

Accepted Answer

A) the Sun's mass and velocity in orbit of the Galactic Center 
B) the Sun's age and period of the Galactic Year 
C) the Sun's orbital velocity and its distance from the Galactic Center 
D) the Sun's mass and its age 
E) the Sun's composition and luminosity 
A) the Sun's mass and velocity in orbit of the Galactic Center 
B) the Sun's age and period of the Galactic Year 
C) the Sun's orbital velocity and its distance from the Galactic Center 
D) the Sun's mass and its age 
E) the Sun's composition and luminosity

Question 16

The RR Lyrae stars all have periods of:

Accepted Answer

A) less than a second. 
B) several minutes. 
C) several hours. 
D) several days. 
E) several weeks. 
A) less than a second. 
B) several minutes. 
C) several hours. 
D) several days. 
E) several weeks.

Question 17

Which is the correct description for the Sun's location in the Galaxy?

Accepted Answer

A) at the outer edge of the bulge, but along the Galactic equator 
B) about 30,000 ly out in the Galactic halo 
C) at the very outer edge of the disk, but in the Galactic plane 
D) in the disk in the inner region of the Sagittarius Arm 
E) in the disk, and about halfway out from the center 
A) at the outer edge of the bulge, but along the Galactic equator 
B) about 30,000 ly out in the Galactic halo 
C) at the very outer edge of the disk, but in the Galactic plane 
D) in the disk in the inner region of the Sagittarius Arm 
E) in the disk, and about halfway out from the center

Question 18

Why was Herschel's strategy for mapping our Galaxy flawed?

Accepted Answer

A) His infrared telescopes couldn't penetrate the dust clouds. 
B) He used globular clusters, lying above the dust in the disk 
C) He relied on visual wavelengths, which are obscured by dust. 
D) He used radio telescopes that didn't give enough resolution. 
E) He assumed Earth was at the extreme edge of the Galaxy. 
A) His infrared telescopes couldn't penetrate the dust clouds. 
B) He used globular clusters, lying above the dust in the disk 
C) He relied on visual wavelengths, which are obscured by dust. 
D) He used radio telescopes that didn't give enough resolution. 
E) He assumed Earth was at the extreme edge of the Galaxy.

Question 19

How does gravity lensing let us find massive dark objects?

Accepted Answer

When a black hole or brown dwarf passes

Question 20

List at least one naked-eye observation that is consistent with the ancient idea that Earth is atthe center of the Milky Way. List at least one naked-eye observation that is inconsistent with thenotion that Earth is at the center of the Milky Way.

Accepted Answer

The actual center of the Galaxy is hidde

Exam 23: The Milky Way Galaxy: a Spiral in Space

Which of the following are most massive and luminous?

All RR Lyrae stars have about the same:

Who discovered the period-luminosity relationship, and why was it so critical?

Henrietta Leavitt first showed the relationship between the mass and luminosity of Cepheidsand their period of pulsation; the brighter, the longer this period.

The core of the Milky Way, Sagittarius A, is a strong radio source in the sky.

Low mass white dwarfs could account for how much of the dark matter in our Galactic halo?

Which of these is NOT typical of the Galaxy's spiral arms?

Harlow Shapley found the Milky Way was:

Who was Henrietta Leavitt, and what did she do to help map the universe?

What observations suggest the mass of the Galaxy goes much farther out than its visibledisk?

S2's orbital radius of 950 A.U. and an orbital period of 15 years are most consistent with S2being a star:

From the center of the Milky Way, 10- kpc-long magnetized jets of high-energy particles areemitted.

Most of the new star formation in the Galaxy is found in the:

How does metal content vary between Population I and II? Why?

What two observations allow us to calculate the Galaxy's mass?

The RR Lyrae stars all have periods of:

Which is the correct description for the Sun's location in the Galaxy?

Why was Herschel's strategy for mapping our Galaxy flawed?

How does gravity lensing let us find massive dark objects?

List at least one naked-eye observation that is consistent with the ancient idea that Earth is atthe center of the Milky Way. List at least one naked-eye observation that is inconsistent with thenotion that Earth is at the center of the Milky Way.

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information From the Cosmos

Spectroscopy: the Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earths Sister Planet

Mars: a Near Miss for Life

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants, Dwarfs, and the Main Sequence

The Interstellar Medium: Gas and Dust Among the Stars

Star Formation: a Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae, Supernovae, and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone

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