Nearby stars have larger parallax than...
Distant stars
The parallax angles of distant stars are...
Too small to measure
True or false? Astronomers have calculated the parallax angles of millions of stars
False
What is a light-year
The distance light travels in a year, 9.5 trillion miles
List three factors that control the apparent brightness of a star as seen from Earth
1. How big
2. How hot
3. How far away
True or false? A third-magnitude star is ten times as bright as a fourth-magnitude star
False
Absolute magnitude
How bright a star actually is
Apparent magnitude
A star's brightness as it appears from Earth
The star Arcturus has a much greater absolute magnitude than the sun but a much lower apparent magnitude. Why is this
Because the sun is closer to Earth
What does a Hertzsprung-Russel diagram show
The absolute magnitude and temperature of stars
About [ ] percent of stars are main-sequnce stars
90 percent
Patterns of stars are called...
Constellations
Because of the gravitational pull between them...
Binary stars, can be used to determine a star's mass
The light shifting, or...
Parallax, in the apparent position of a nearby star due to the orbital motion of Earth is used to measure star distance
In ranking stars according to their...
Apparent magnitude, the larger the number is, the dimmer the star appears from Earth
The faintest stars...
Lower-right corner
Variable stars such a Cepheid variables and stars experiencing a nova show fluctuations in...
Brightness
Emmision nebulae are made mostly of hydrogen, whereas...
Reflective nebulae
A star is not considered born until the process of...
Nuclear fusion begins
In a red giant, both hydrogen and...
Helium are used to produce energy
All stars eventually become either a white dwarf, a neutron star, or a...
Black dwarf
Presently, our sun is considered to be in the...
Main-sequence stage of its life cycle
Of the three types of galaxies -spiral, elliptical, and irregular- the Milky Way is a...
Spiral galaxy
Galaxies differ in their shape...
Size, and age of their stars
The [ ] indicates whether a star or other body in space is moving away from Earth or towards Earth
Doppler effect
How do the deaths of low-mass, medium-mass, and high-mass stars differ
Low mass stars immediately go to white dwarf stars then black dwarf. Medium mass stars go to red giant stars and then white dwarf and then black dwarf. The high-mass stars go from red supergiant to supernova, and then either a neutron star, or a black hol
How does the red shift phenomenon indicate that the universe is expanding
The closer stars move away from us slowly, and the stars that are farther away at a faster pace, and then the stars that are really far away from us, they will move away really fast. This is consistent with an expanding universe.
Given that black holes absorb all light, how is it possible for scientists to see or to study black holes
You see black, but they study everything that is effected around it
How would you classify types of galaxies according to the age of the stars found in them
Elliptical galaxies have old stars. Irregular galaxies have young stars. Spiral galaxies have a mixture of old stars at their center bulges and young stars at their spiral arms.
What is the process by which a star is born
A cloud of dust and gas is floating in space and it all has gravitational pull. It all then pulls together, heat and pressure from the gas above it pushes it altogether and its density and its temperature increases until nuclear fusion ignites and a star
List in order the labeled stages that a medium-mass star goes through during its "life
a. ______dust and gasses_(Nebula)____________ e.
___________Variable stage_________________
b. __________Protostar_____________________ f. ___________Planetary Nebula Stage_________
c. __________Main-sequence star_____________ g. __________White Dwarf Sta
A [ ] is a developing star not yet hot enough to engage in nuclear fusion
Protostar
True or false? All stars eventually run out of fuel and collapse due to gravity
True
True or false? An average star spends 90 percent of its life as a helium-burning main-sequence star
True
How can a Hertzsprung-Russell diagram be used to show the evolution of a star
The Hertzprung Russell diagram shows how the luminosities and surface temperatures of stars are linked.
Match each death description with its star.
Forms a red giant, which then collapses into a red dwarf and forms a planetary nebula
Low-mass star
Blows up in a supernova explosion
Massive star
Does not form a red giant; collapses directly into a white dwarf
Medium-mass star
Describe the stages the sun has gone through and will go through during its evolution
The sun is in its main sequence stage. It has gone through the dust and gasses stage, and the protostar stage. The sun will stay in the main sequence stage for about another 5 billion years, and then go on to the Red Giant Stage> Helium Flash > Planetary
A [ ] is a neutron star that rotates and generates radio waves
Pulsar star
Remnant of a supernova event; similar to a large atomic nucleus
Neutron star
Small dense object formed from the remnants of a star at least three times as massive as the sun
White dwarf
Remnant of a low-mass or medium-mass star
Black hole
What color will a star be with a surface temperature of 5000-6000K
Yellow
The mass of a star can be determined by studying...
Binary star systems
Which is true about using parallax to measure distance to stars
The closer the star, the larger is the parallax
Approximately how long is a light-yeaar
9.5 trillion km
What is not a factor that affects the apparent brightness of a star as seen from Earth
How old the star is
Star A is farther away from Earth than star B. Both stars have the same absolute magnitude. Which of the following is true about their apparent magnitude
Star B will have a greater apparent magnitude
A Hertzsprung-Russel diagram is used to show the relationship between...
Temperature and absolute magnitude
About 90 percent of the stars on the Hertzsprung-Russel diagram are...
Main-sequence stars
Before a star is born, the matter that will become the star exists as a...
Cool, dark nebula
A star is thought to be born when...
A protostar reaches a temperature high enough for nuclear fusion to begin
Into what life cycle stage will the sun enter next
Red giant stage
What will be the final stage in our sun's life cycle
Black dwarf stage
All stars, regardless of their size, eventually...
Run out of fuel and collapse
What remains after a low-mass or medium-mass star dies
White dwarf
At its nucleus, the Milky Way galaxy is about 100,000 light-years wide and about...
10,000 light-years thick
According to information received from radio telescopes, where is our sun positioned in the Milky Way
Within one of the spirals
About 60 percent of all known galaxies are classified as...
Elliptical galaxies
Scientists know that the universe is expanding because of the...
Red shift of distant galaxies
According to the big bang theory, the entire universe began as a...
Dense, hot, supermassive tiny ball
What is supportive evidence of the big bang theory
Cosmic background radiation
List three properties of stars
1. Color
2.Temperature
3. Mass
True or false? A star's color can tell you what its approximate temperature is
True
What are binary stars
A system of two stars in which one star revolves around the other or both revolve around a common center.
Binary stars can be used to determine the...
Mass of a star
The apparent change in position of a star when seen from opposite sides of Earth's orbit is called...
Parallax