Question 1

From stage 4 to stage 7 of star formation, the object plotted on the H-R diagram moves sothat:

Accepted Answer

A) its luminosity decreases, while its temperature increases. 
B) its luminosity decreases, while its temperature stays the same. 
C) its luminosity increases, while its temperature increases. 
D) its luminosity increases, while its temperature stays the same. 
E) its luminosity stays the same, and its temperature stays the same. 
A) its luminosity decreases, while its temperature increases. 
B) its luminosity decreases, while its temperature stays the same. 
C) its luminosity increases, while its temperature increases. 
D) its luminosity increases, while its temperature stays the same. 
E) its luminosity stays the same, and its temperature stays the same. A

Question 2

At the end of the Kelvin-Helmholtz contraction, a star is hundreds of times brighter than itwill be as a main sequence star.

Accepted Answer

A) True 
 B)False  True

Question 3

An interstellar gas cloud has the mass to form hundreds of stars. What generally happens to it?

Accepted Answer

The cloud fragments into smaller clouds and forms many stars.

Question 4

The most important fact about a cluster of stars that makes them useful for studying starformation is that:

Accepted Answer

A) all the stars formed from the same cloud. 
B) all the stars formed at about the same time. 
C) all the stars are at the same distance from Earth. 
D) all the stars have the same chemical composition. 
E) all the stars are the same spectral type. 
A) all the stars formed from the same cloud. 
B) all the stars formed at about the same time. 
C) all the stars are at the same distance from Earth. 
D) all the stars have the same chemical composition. 
E) all the stars are the same spectral type.

Question 5

Which relationship concerning the mass of protostars is FALSE?

Accepted Answer

A) The more massive ones will reach the main sequence first. 
B) The more massive ones will be the hottest and most luminous. 
C) The more massive ones will be made of the heaviest elements. 
D) The more massive ones are so luminous they ionize the gas, hence red H II regions. 
E) The more massive ones create a lot of ultraviolet as well as visible light. 
A) The more massive ones will reach the main sequence first. 
B) The more massive ones will be the hottest and most luminous. 
C) The more massive ones will be made of the heaviest elements. 
D) The more massive ones are so luminous they ionize the gas, hence red H II regions. 
E) The more massive ones create a lot of ultraviolet as well as visible light.

Question 6

Shock waves from supernovae disrupt an interstellar cloud and prevent it from forming stars.

Accepted Answer

A) True 
 B)False

Question 7

During stage 3 of star formation, the dense, opaque region at the center of the cloud is calleda

Accepted Answer

A) Herbig-Haro object. 
B) T Tauri star. 
C) protostar. 
D) protoplanetary nebula. 
E) zero-age main sequence star. 
A) Herbig-Haro object. 
B) T Tauri star. 
C) protostar. 
D) protoplanetary nebula. 
E) zero-age main sequence star.

Question 8

Why are star clusters almost ideal "laboratories" for stellar studies?

Accepted Answer

A) All stars in the cluster are the same size and luminosity. 
B) Their combined light makes them much easier to spot from a distance. 
C) Stars in clusters have the same age, similar composition, and are at the same distance away. 
D) Stars in clusters are all relatively young and therefore shine brightly. 
E) Like our Sun, stars in clusters are always located in the plane of the Milky Way Galaxy. 
A) All stars in the cluster are the same size and luminosity. 
B) Their combined light makes them much easier to spot from a distance. 
C) Stars in clusters have the same age, similar composition, and are at the same distance away. 
D) Stars in clusters are all relatively young and therefore shine brightly. 
E) Like our Sun, stars in clusters are always located in the plane of the Milky Way Galaxy.

Question 9

Why does gravitational contraction halt in collapsing protostars?

Accepted Answer

Gravitational contraction heat

Question 10

Most stars are usually formed singularly or as binaries, not in clusters.

Accepted Answer

A) True 
 B)False

Question 11

What are some complications that interfere with star formation?

Accepted Answer

A rapidly spinning nebula may

Question 12

What stage of star formation is ZAMS?

Accepted Answer

At stage 7, the zero age main

Question 13

The Great Explosion of Eta Carinae expelled about ________ solar masses of material andreleased about as much visible energy as a supernova.

Accepted Answer

The answer of The Great Explosion of Eta Carinae expelled...

Question 14

In stage 6 or 7 of the formation of a large cluster of stars, a nebula is formed around thecluster. This happens because:

Accepted Answer

A) the number of stars is so great and so intense that the gas from the original cloud is ionized. 
B) the stars are out of their cocoons of dust and their radiation ionizes the gas from the originalcloud. 
C) there are brown dwarfs everywhere in between the stars, so the gas is lit up by their low-intensity light. 
D) there are thousands of Sun-like stars with planets around them and the formation of planetsionizes the leftover gas. 
E) there are massive O and B stars emitting high energy photons that ionize the remainder of thecloud. 
A) the number of stars is so great and so intense that the gas from the original cloud is ionized. 
B) the stars are out of their cocoons of dust and their radiation ionizes the gas from the originalcloud. 
C) there are brown dwarfs everywhere in between the stars, so the gas is lit up by their low-intensity light. 
D) there are thousands of Sun-like stars with planets around them and the formation of planetsionizes the leftover gas. 
E) there are massive O and B stars emitting high energy photons that ionize the remainder of thecloud.

Question 15

Most stars, probably all stars, formed:

Accepted Answer

A) in a binary system. 
B) in a triple system. 
C) in a cluster of stars. 
D) all by themselves. 
E) There is no theory to predict this. 
A) in a binary system. 
B) in a triple system. 
C) in a cluster of stars. 
D) all by themselves. 
E) There is no theory to predict this.

Question 16

The evolution of a protostar slows significantly as it approaches the main sequence.

Accepted Answer

A) True 
 B)False

Question 17

What are thought to be some possible causes of triggering the contraction of an interstellarcloud?

Accepted Answer

The shockwave from the formati

Question 18

Many of the brightest stars we see are only a few million years old.

Accepted Answer

A) True 
 B)False

Question 19

The stars found in nebulae like the Orion Nebula probably formed:

Accepted Answer

A) a few million years ago. 
B) about 10 million years ago. 
C) hundreds of millions of years ago. 
D) billions of years ago. 
E) at the beginning of the universe. 
A) a few million years ago. 
B) about 10 million years ago. 
C) hundreds of millions of years ago. 
D) billions of years ago. 
E) at the beginning of the universe.

Question 20

The fundamental difference between a protostar and a star is that the latter has nuclear fusionas its energy source and the former does not.

Accepted Answer

A) True 
 B)False

Exam 19: Star Formation: a Traumatic Birth

From stage 4 to stage 7 of star formation, the object plotted on the H-R diagram moves sothat:

At the end of the Kelvin-Helmholtz contraction, a star is hundreds of times brighter than itwill be as a main sequence star.

An interstellar gas cloud has the mass to form hundreds of stars. What generally happens to it?

The most important fact about a cluster of stars that makes them useful for studying starformation is that:

Which relationship concerning the mass of protostars is FALSE?

Shock waves from supernovae disrupt an interstellar cloud and prevent it from forming stars.

During stage 3 of star formation, the dense, opaque region at the center of the cloud is calleda

Why are star clusters almost ideal "laboratories" for stellar studies?

Why does gravitational contraction halt in collapsing protostars?

Most stars are usually formed singularly or as binaries, not in clusters.

What are some complications that interfere with star formation?

What stage of star formation is ZAMS?

The Great Explosion of Eta Carinae expelled about ________ solar masses of material andreleased about as much visible energy as a supernova.

In stage 6 or 7 of the formation of a large cluster of stars, a nebula is formed around thecluster. This happens because:

Most stars, probably all stars, formed:

The evolution of a protostar slows significantly as it approaches the main sequence.

What are thought to be some possible causes of triggering the contraction of an interstellarcloud?

Many of the brightest stars we see are only a few million years old.

The stars found in nebulae like the Orion Nebula probably formed:

The fundamental difference between a protostar and a star is that the latter has nuclear fusionas its energy source and the former does not.

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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