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Stars
Section 20something.1.2.3
50
Science
8th Grade
02/20/2008

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Cards

Term
What color are stars with the highest surface temperature ?
Definition
Blue
Term
What color are the stars with the coldest surface temperature ?
Definition
Red
Term
How do astronomers determine the mass of a star ?
Definition

Binary Star systems !

Term

What is the magnitude associated with the brightest star ?

Definition
-20 ;;  The lesser the number, the brighter
Term
What affects the star's apparent magnituede ?
Definition
Distance from star
Term

What is apparent magnitude?

Definition
How bright the star appears from earth
Term
What is a light year ?  How many kilometers is a light year ?
Definition
A light year is the distance time travels in a year ;; 9.5 trillion km in one light year
Term
What is magnitude?
Definition
How bright the star is
Term
What is parallax ?
Definition
How we measure distance of stars
Term
What does parallax measure ?
Definition
Distance of stars
Term
When is parallax not used ?
Definition
When the star is too far away
Term
How are stellar distances usually expressed ?
Definition
Light years
Term
What are the types of nebulae ?
Definition
Emission and reflection
Term
What causes the difference in the brightness of 2 stars when they have the same surface temperature ?
Definition
Distance
Term
What color main-sequence stars are the most massive ? What color are the main sequence stars that are the least massive ?
Definition
Highest~blue
Lowest~red
Term
What does a HR diagram show the relationship between ?
Definition
absolute magnitude and temperature
Term
Roughly what percentage of stars on the HR diagram are main-sequence stars ?
Definition
90%
Term
What is another name for the interstellar matter that will eventually form a star ?
Definition
nebulae
Term
When is a star said to be " born " ?
Definition
When the core of the protostar reches 10 million kelvin
Term
What is the force most responsible for the formation of a star ?
Definition
Gravity
Term
How do massive stars end their lives ?
Definition
Supernova
Term
What galaxy does or sun belong, what type of galaxy is it, and where in that galaxy is the sun located ?
Definition
Milky way ;; Spiral galaxy ;; On the arms
Term
What can't light escape ?
Definition
Black Holes
Term
What do all stars eventually run out of ? What occurs when that happens ?
Definition
Hydrogen ;; Becomes a giant
Term
What do the nuclear reactions in the core of a Red Giant convert helium to ?
Definition
Carbon
Term
Before being engulfed, what happens to the matter that is pulled into a black hole ?
Definition
It gives off X-Rays
Term
What does a main-sequence star become after it has worn out the fuel in its core ?
Definition
Giant
Term
What type of star is our sun ?
Definition
Average // Main-Sequence
Term
What will the next stage of our sun be ?
Definition
Giant
Term
What will be the final stage in the sun's life cycle ?
Definition
Black Dwarf
Term
What are 60% of all known galaxies classified as ?
Definition
Eliptical
Term
What is the largest object ?
Definition
Super Giant
Term
What indicates that the universe is expanding ?
Definition
Doppler shift to red
Term
According to the big bang theory, when did the universe begin ?
Definition
13.7 billion years ago
Term
What are patterns of stars called ?
Definition
Constellations
Term
What were constellations originally named in honor of ?
Definition
Gods // Heroes
Term
What is a protostar ?
Definition
Beginning of stars life . Developing star, not hot enough to behin nuclear fusion .
Term
What are pulsars ?
Definition
Flickering stars that release radio images
Term
What are the most dense stars ?
Definition
Neutron stars
Term
What marks the beginning of the universe ?
Definition
Big bang
Term
What is the doppler effect ? When there is a greater shift in the spectra, what does it mean ?
Definition
When the frequency and wavelength of sound waves are effected by relative motion ;; The object is moving faster
Term
Name three major differences among galaxies .
Definition
Size, color, shape, amount of stars
Term
How much time of an average size stars life is spent in the main sequence stage ?
Definition
About 10 billion years
Term
When you know the color of a star, you can then find what property ?
Definition
Temperature
Term
Why are massive stars lives faster than stars that are less massive ?
Definition
More hydrogen, which is burned quicker
Term
Why are red giants red colored in appearence ?
Definition
Because they are cooler
Term
What is a galaxy ?
Definition
Groups of stars, dusts, and gases held together by gravity
Term
Which galaxies contain mainly young stars ?
Definition
Irregular
Term
What does hubble's law state?
Definition
The universe expands
Term
What proves the universe is expanding ?
Definition
Cosmic background radiation // shift to red
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