astronomy

Question 1

if space if infinite with stars scattered randomly throughout it, then no matter where you look, you must see a star. therefore the entire sky should blaze like the surface of the sun

Answer 1

olbers paradox

Question 2

his relativity equations showed a universe that was either expanding or contracting

Answer 2

Albert Einstein

Question 3

discovered our universe is expanding

Answer 3

Edwin Hubble

Question 4

galaxies emit light and expand into space, the wavelength of light gets stretched
this increase in wavelength produces a redshift
distant galaxies have larger red shifts then nearby galaxies

Answer 4

cosmological redshift

Question 5

cataclysmic event which caused matter to begin expanding
this expansion slaves olbers paradox
age of the universe is approximately 13.7 billion years
observable universe

Answer 5

Big Bang theory

Question 6

galaxies themselves do not expand
the space between galaxies is expanding
ga
dies are kept together by their mutual gravity

Answer 6

expanding universe

Question 7

early universe must have been very hot
the universe has expanded greatly since the Big Bang
CMB is “left over” heat from the Big Bang

Answer 7

cosmic microwave background radiation

Question 8

system containing millions or billions of stars
we are part of the Milky Way Galaxy
universe contains several billion

Answer 8

galaxies

Question 9

lens shaped disks

bright nucleus

Answer 9

spiral

Question 10

lens shared with arms

bright nucleus

Answer 10

barred spiral

Question 11

lens shaped but no bright center or arms

Answer 11

elliptical

Question 12

small and faint

non-descript

Answer 12

irregular

Question 13

diameter is 140000 light years across
we are about 23000 light years from the center of the Galaxy
we are part of a local group
small cluster of 17 galaxies

Answer 13

Milky Way Galaxy

Question 14

size can very greatly
can be smaller than earth
can be 2000 times the size of our sun
largest one has a diameter that is nearly 19 times the distance between earth and sun

Answer 14

stars

Question 15

most of these are the density of our sun

Answer 15

stars

Question 16

main,y hydrogen and helium

Answer 16

stars

Question 17

typically contain about 2% other heavier elements

Answer 17

stars

Question 18

clouds of gas and dust

Answer 18

nebulae

Question 19

glowing cloud sections

eventually hot enough to cause fusion of hydrogen

Answer 19

protostars

Question 20

balance of energy released with gravity

remain stable for many billions of years

Answer 20

stable state

Question 21

name the 4 types of stars

Answer 21

super Giants
giants
main sequence stars
white dwarfs

Question 22

plop lots stars using surface temp in kelvin and a stars absolute magnitude
shows stars current type
spectral type

Answer 22

hertzburg Russell diagram

Question 23

stars are classified by their temp and color

Answer 23

spectral type

Question 24

VERY large, but cool
give off lots of light due to their size
ex. Betelgeuse, Antares, Polaris

Answer 24

super Giants

Question 25

large, but cool give off a lot of light not as bright as super Giants ex. Arcturus

Answer 25

Giants

Question 26

starting mass determines temp the larger the starting mass the hotter the sun

Answer 26

main sequence stars

Question 27

the higher the surface temp...

Answer 27

the bluer the star

Question 28

the cooler the surface temp...

Answer 28

the redder the star

Question 29

very hot about the size of earth but 100,000 times more dense do not produce much light due to small size

Answer 29

white dwarfs

Question 30

a set of stars seen from earth that makes a shape different cultures have different constellations and names often have mythical or historical significance ex. Big Dipper and zodiac signs

Answer 30

constellations

Question 31

not close together or in our Galaxy

Answer 31

stars

Question 32

why can we only see certain constellations during different seasons

Answer 32

the earths position

Question 33

constellations that appear to move around Polaris caused by the earth turning on its axis they never set

Answer 33

circumpolar constellations

Question 34

symbol Is a little m how bright it looks in the sky from earth stars that are far are dim stars that are close are bright

Answer 34

apparent magnitude

Question 35

brightest star in the night sky

Answer 35

Sirius

Question 36

dimmest star we can see is...

Answer 36

+6

Question 37

symbol is a big M scale compares all stars as if they were the exact same distance from earth distance is 10 parsecs

Answer 37

absolute magnitude

Question 38

true brightness

Answer 38

absolute magnitude

Question 39

why is the sun so bright

Answer 39

it is very close to earth

Question 40

how much closer/ farther

Answer 40

distance factor

Question 41

star whose magnitude changes in a cycle cycle can last days or years ex. Cepheus the king

Answer 41

variable star

Question 42

what makes variable stars hotter

Answer 42

contraction

Question 43

what makes a star cooler

Answer 43

expansion

Question 44

controlled by the length of the brightness cycle | the longer the period the longer the this is

Answer 44

absolute magnitude

Question 45

unchanging universe | infinitely old

Answer 45

sir issac Newton