Question 1

A stage 4 object can be plotted on the H-R diagram. At this stage, the star will appear:

Accepted Answer

A) in the middle left of the diagram. 
B) in the middle right of the diagram. 
C) just on the bottom right of the main sequence. 
D) down and to the left of where it will be when it is a main sequence star. 
E) in the middle of the main sequence. 
A) in the middle left of the diagram. 
B) in the middle right of the diagram. 
C) just on the bottom right of the main sequence. 
D) down and to the left of where it will be when it is a main sequence star. 
E) in the middle of the main sequence.

Question 2

Star clusters have been observed within dark nebulae with:

Accepted Answer

A) optical movies made over decades. 
B) radio interferometers. 
C) infrared observations. 
D) the Chandra X-ray Observatory. 
E) ultraviolet light creating the emission nebulae. 
A) optical movies made over decades. 
B) radio interferometers. 
C) infrared observations. 
D) the Chandra X-ray Observatory. 
E) ultraviolet light creating the emission nebulae.

Question 3

The red evolutionary track illustrated in the figure above (similar to fig 19.6 in your textbook),that goes from point 4 to 5 to 6 to 7 shows:

Accepted Answer

A) a star nearing the end of its life and becoming a red giant. 
B) a star nearing the end of its life and becoming a white dwarf. 
C) a protostar forming into a main sequence star. 
D) the changes that happen to a star during its red giant phase. 
E) the locations on the H-R diagram for a small cluster of stars. 
A) a star nearing the end of its life and becoming a red giant. 
B) a star nearing the end of its life and becoming a white dwarf. 
C) a protostar forming into a main sequence star. 
D) the changes that happen to a star during its red giant phase. 
E) the locations on the H-R diagram for a small cluster of stars.

Question 4

Brown dwarfs are most easily detected on which portion of the electromagnetic spectrum?

Accepted Answer

A) X-ray 
B) ultraviolet 
C) visible light 
D) infrared 
E) radio 
A) X-ray 
B) ultraviolet 
C) visible light 
D) infrared 
E) radio

Question 5

A fragment of a collapsing gas cloud that comes to equilibrium with a central temperature of4 million K will become a:

Accepted Answer

A) black hole. 
B) brown dwarf. 
C) black dwarf. 
D) T Tauri star. 
E) stage 1 protostar. 
A) black hole. 
B) brown dwarf. 
C) black dwarf. 
D) T Tauri star. 
E) stage 1 protostar.

Question 6

How long does it take an M class star to reach the main sequence, compared to a solar typestar?

Accepted Answer

A) a tenth as long 
B) about the same, 30 million years 
C) about twice as long 
D) about twenty times longer 
E) longer than the age of the Galaxy 
A) a tenth as long 
B) about the same, 30 million years 
C) about twice as long 
D) about twenty times longer 
E) longer than the age of the Galaxy

Question 7

Protostars can be observed in:

Accepted Answer

A) the Crab Nebula. 
B) the Andromeda Galaxy. 
C) the Orion Nebula. 
D) our Solar System. 
E) the Helix Nebula. 
A) the Crab Nebula. 
B) the Andromeda Galaxy. 
C) the Orion Nebula. 
D) our Solar System. 
E) the Helix Nebula.

Question 8

Discuss the relationship between young stars and the interstellar medium.

Accepted Answer

Young stars give off ultraviolet radiati

Question 9

A protostar of 20 solar masses should form a star that will stay on the main sequence twentytimes longer than our Sun.

Accepted Answer

A) True 
 B)False

Question 10

What factors can complicate the collapse of an interstellar cloud into a star?

Accepted Answer

The initial spin of the cloud and the co

Question 11

What is characteristic of a main sequence star?

Accepted Answer

A) It has a mass less than the Sun's. 
B) It has rapid rotation and a strong stellar wind. 
C) Nuclear fusion in the core varies due to the amount of gravitational contraction that occursand which heavy elements are produced. 
D) The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rateradiated from the surface. 
E) All of the above are correct. 
A) It has a mass less than the Sun's. 
B) It has rapid rotation and a strong stellar wind. 
C) Nuclear fusion in the core varies due to the amount of gravitational contraction that occursand which heavy elements are produced. 
D) The rate of nuclear energy generated in the hydrogen to helium fusing core equals the rateradiated from the surface. 
E) All of the above are correct.

Question 12

Rotation of the protostar helps generate the magnetic fields and bipolar flows.

Accepted Answer

A) True 
 B)False

Question 13

As a protostar evolves from stage 4 to stage 6, it gets hotter but much less bright.

Accepted Answer

A) True 
 B)False

Question 14

Brown dwarfs form:

Accepted Answer

A) in the nebular disk around another object. 
B) outside of a galaxy. 
C) in planetary nebulae. 
D) as the result of a supernova. 
E) in their own contracting fragment of a molecular cloud. 
A) in the nebular disk around another object. 
B) outside of a galaxy. 
C) in planetary nebulae. 
D) as the result of a supernova. 
E) in their own contracting fragment of a molecular cloud.

Exam 19: Star Formation: a Traumatic Birth

A stage 4 object can be plotted on the H-R diagram. At this stage, the star will appear:

Star clusters have been observed within dark nebulae with:

The red evolutionary track illustrated in the figure above (similar to fig 19.6 in your textbook),that goes from point 4 to 5 to 6 to 7 shows:

Brown dwarfs are most easily detected on which portion of the electromagnetic spectrum?

A fragment of a collapsing gas cloud that comes to equilibrium with a central temperature of4 million K will become a:

How long does it take an M class star to reach the main sequence, compared to a solar typestar?

Protostars can be observed in:

Discuss the relationship between young stars and the interstellar medium.

A protostar of 20 solar masses should form a star that will stay on the main sequence twentytimes longer than our Sun.

What factors can complicate the collapse of an interstellar cloud into a star?

What is characteristic of a main sequence star?

Rotation of the protostar helps generate the magnetic fields and bipolar flows.

As a protostar evolves from stage 4 to stage 6, it gets hotter but much less bright.

Brown dwarfs form:

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

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

The Milky Way Galaxy: a Spiral in Space

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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