Question 1

The apparent magnitude of the Sun is -26, while Sirius has an apparent magnitude of -1; howmuch brighter does the Sun appear than Sirius?

Accepted Answer

This is a difference of 25 mag

Question 2

A star similar to Sirius A has a temperature of about 10,000 K, and a luminosity of around 25times that of the Sun. Approximately what is its radius?

Accepted Answer

Using T in units of 5000 K, that gives T

Question 3

Why is the main sequence main? Why are these stars so common?

Accepted Answer

While their masses, luminosities, and te

Question 4

What is the single most important characteristic in determining the course of a star'sevolution?

Accepted Answer

A) density 
B) absolute brightness 
C) distance 
D) surface temperature 
E) mass 
A) density 
B) absolute brightness 
C) distance 
D) surface temperature 
E) mass

Question 5

In an eclipsing binary, the longer the stages of the eclipse take, the ________ the star.

Accepted Answer

The answer of In an eclipsing binary, the longer the...

Question 6

The motion of a star towards or away from us is called its:

Accepted Answer

A) transverse motion. 
B) radial motion. 
C) parallax shift. 
D) Doppler shift. 
E) true space motion. 
A) transverse motion. 
B) radial motion. 
C) parallax shift. 
D) Doppler shift. 
E) true space motion.

Question 7

Which type of binary can have their sizes measured directly by photometry?

Accepted Answer

A) virtual 
B) visual 
C) eclipsing 
D) spectroscopic 
E) astrometric 
A) virtual 
B) visual 
C) eclipsing 
D) spectroscopic 
E) astrometric

Question 8

About how many stars can be seen from somewhere on Earth with the naked eye?

Accepted Answer

A) 600 
B) 6,000 
C) 600,000 
D) 6,000,000 
E) uncountably many 
A) 600 
B) 6,000 
C) 600,000 
D) 6,000,000 
E) uncountably many

Question 9

Alpha Centauri A and B have an average orbital separation of about 23 A.U. and a period ofabout 80 years. Approximately what is the sum of their masses? If we presume that AlphaCentauri A is a star like our Sun, what is Alpha Centauri B's mass?

Accepted Answer

@#IMG-DLM& olar mass

Question 10

All classes of binary stars yield the basic information on stellar ________.

Accepted Answer

The answer of All classes of binary stars yield the...

Question 11

What is the relationship between a star's mass and its lifetime?

Accepted Answer

The more massive a s

Question 12

On the main sequence, almost all stars have radii between about 0.1 and 10 times the Sun.

Accepted Answer

A) True 
 B)False

Question 13

How might the most common occurring stars be described, based on our stellarneighborhood?

Accepted Answer

A) white dwarfs 
B) K giants 
C) G main sequence 
D) A main sequence 
E) M main sequence 
A) white dwarfs 
B) K giants 
C) G main sequence 
D) A main sequence 
E) M main sequence

Question 14

First magnitude Spica appears 2.5 times brighter than second magnitude Polaris.

Accepted Answer

A) True 
 B)False

Question 15

About how many stars has the Hipparcos mission given us accurate distance data on?

Accepted Answer

A) about 3,000, about half of what you can see with the naked eye alone 
B) over 6000, the visible naked eye stars and some seen in binoculars 
C) 60,000, those within about 100 light-years of us 
D) a million, those with parallaxes of .005" or larger 
E) over 100 billion, almost every star in the galaxy 
A) about 3,000, about half of what you can see with the naked eye alone 
B) over 6000, the visible naked eye stars and some seen in binoculars 
C) 60,000, those within about 100 light-years of us 
D) a million, those with parallaxes of .005" or larger 
E) over 100 billion, almost every star in the galaxy

Exam 17: The Stars: Giants, Dwarfs, and the Main Sequence

The apparent magnitude of the Sun is -26, while Sirius has an apparent magnitude of -1; howmuch brighter does the Sun appear than Sirius?

A star similar to Sirius A has a temperature of about 10,000 K, and a luminosity of around 25times that of the Sun. Approximately what is its radius?

Why is the main sequence main? Why are these stars so common?

What is the single most important characteristic in determining the course of a star'sevolution?

In an eclipsing binary, the longer the stages of the eclipse take, the ________ the star.

The motion of a star towards or away from us is called its:

Which type of binary can have their sizes measured directly by photometry?

About how many stars can be seen from somewhere on Earth with the naked eye?

Alpha Centauri A and B have an average orbital separation of about 23 A.U. and a period ofabout 80 years. Approximately what is the sum of their masses? If we presume that AlphaCentauri A is a star like our Sun, what is Alpha Centauri B's mass?

All classes of binary stars yield the basic information on stellar ________.

What is the relationship between a star's mass and its lifetime?

On the main sequence, almost all stars have radii between about 0.1 and 10 times the Sun.

How might the most common occurring stars be described, based on our stellarneighborhood?

First magnitude Spica appears 2.5 times brighter than second magnitude Polaris.

About how many stars has the Hipparcos mission given us accurate distance data on?

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 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

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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