The Milky Way Test/Notes

Question 1

How long does it take the earth to make one complete circuit of the Milky Way?

Answer 1

200 million years

Question 2

We call the cluster of galaxies in the local region of space this…

Answer 2

The local group (50 galaxies in this)

Question 3

Most of our galaxy is invisible for us because this blocks our way?

Answer 3

Dust clouds/dark matter

Question 4

We are located in this part of the Milky Way

Answer 4

Orion spur

Question 5

How many stars are in our Milky Way?

Answer 5

200 to 400 billion stars

Question 6

Why is space black?

Answer 6

There isn’t enough gas/dust to scatter the light

Question 7

What portion of the Galaxy is controlling the Suns orbit?

Answer 7

Every thing inside of our orbit

Question 8

How many solar masses is our Milky Way?

Answer 8

600 billion solar masses

Question 9

Some astronomers feel that this mass may be made of low intensity types of stars called?

Answer 9

White dwarf
Brown dwarfs
(MACHOS)

Question 10

The region that contains mass, but cannot be seen is called this?

Answer 10

The dark halo

Question 11

Galaxies can be created by these…

Answer 11

Dark filaments: pulls the dark matter together in the first place

Question 12

Mathematical representation of keplers 3rd law?

Answer 12

P^2=(4p^2a^3)/g(m+M)

Question 13

We look into the center of the Galaxy in what wavelengths?

Answer 13

X-rays and/or gamma rays

Question 14

We know that there is something that massive at the center of our galaxy because of the fact that stars nearby are doing what?

Answer 14

Orbiting quickly

Question 15

True or false… The black hole at the center of the Galaxy is pulling everything into it

Answer 15

False

Question 16

How many galaxies are colliding with the Milky Way?

Answer 16

2

Question 17

The sombrero Galaxy holds what may be a supermassive black hole of how many solar masses?

Answer 17

1,000,000,000

Question 18

Using this type of observation we see that the Galaxy rotates at different speeds

Answer 18

Radio

Question 19

Where do the arms of the milky way rotate the fastest?

Answer 19

The center

Question 20

In the transient spiral theory the arms…

Answer 20

Come and go

Question 21

The density theory can be compared to this real life situation

Answer 21

Traffic jam

Question 22

Theories state that eventually the arms will wind up and become indistinguishable. The 3 theories are…

Answer 22

1. Density wave
2. Self propagating
3. Transient spiral

Question 23

How many years ago did we think we were in the center of the universe?

Answer 23

500 years ago

Question 24

Does the universe have an ending point?

Answer 24

No

Question 25

The Milky Way is how many light years across?

Answer 25

99,000 light years

Question 26

These types of stars were used to measure distance

Answer 26

Variable stars

Question 27

How many kilo secs in a parsec?

Answer 27

1,000

Question 28

2 types of variable stars

Answer 28

Cataclysmic | Intrinsic

Question 29

Astronomers use this law and luminosity to calculate the distance from us

Answer 29

Inverse square law

Question 30

2 types of pulsating intrinsic stars

Answer 30

Cepheid | RR Lyrae

Question 31

All variable stars have the same luminosity of...

Answer 31

100 times our sun

Question 32

Many of the RR Lyrae stars were found in these groupings of stars that surround the Galaxy

Answer 32

Globular clusters

Question 33

The entire area of the Galaxy is known as this..?

Answer 33

Galactic halo

Question 34

The "hub" of the Galaxy is where?

Answer 34

The center of the universe

Question 35

The halo is lacking what 2 items that are abundant in the rest of the Galaxy?

Answer 35

Gas and dust

Question 36

The oldest stars in the Galaxy are found where? (3 places)

Answer 36

Halo Budge Inner disk

Question 37

How fast are we moving through the Galaxy?

Answer 37

220 km/sec

Question 38

The orbits of objects in the halo don't have any set pattern. They are...?

Answer 38

Random

Question 39

How long ago did our galaxy form?

Answer 39

10 billion years

Question 40

A nebula that collapses under its own gravity to form a Galaxy is called a?

Answer 40

Pepto galaxy

Question 41

When a galactic nebula collapses it will begin to do what?

Answer 41

Spin/rotate

Question 42

Why will our galaxy begin to behave in the manner that it does as it collapses? What theory is involved?

Answer 42

Angular momentum

Question 43

Is our galaxy on a collision course?

Answer 43

Yes

Question 44

Within the "leftovers" of the galaxies are groupings of stars called?

Answer 44

Globular clusters

Question 45

The "nursery" of the Galaxy is where?

Answer 45

The outer disk

Question 46

The globular clusters in the halo are primarily made up of stars what color? What does this tell us?

Answer 46

Red... The stars are old

Question 47

We are this type of Galaxy?

Answer 47

Spiral

Question 48

The first group of stars that form w/in a Galaxy?

Answer 48

Globular clusters

Question 49

The area that surrounds the entire Milky way in all dimensions is called this?

Answer 49

Dark halo

Question 50

The arms of the Galaxy are found here

Answer 50

Outer/inner disc

Question 51

The central part of the Galaxy is also known as

Answer 51

Bulge

Question 52

How many light years in a parsec?

Answer 52

3.3

Question 53

An example of a cataclysmic variable star is?

Answer 53

Nova Type 1A

Question 54

Stellar vs interstellar matter?

Answer 54

``` Stellar= made or related stars Interstellar= clouds of gas and dust (I.e. Nebulas) isolated in space. No individual stars ```

Question 55

Cataclysmic star

Answer 55

* requires a binary companion * star is some type of nova * short and no recovering periods of brightness * all at once * can't predict next occurrence

Question 56

Intrinsic star

Answer 56

* changes brightness because of rapid changes in diameter * predictable * give us average brightness * just 1 star

Question 57

Cepheid Star

Answer 57

* for stars in other galaxies * periods of brightness 1-100 days * high mass star * long period of brightness * not really precise, but good at long distance * don't use because they're rare

Question 58

RR Lyrae Stars

Answer 58

* hard to detect but lots of them * in our own Galaxy * periods of brightness under a day * low mass star. Smaller= less variation * very accurate in determining distance, not as bright

Question 59

The density wave theory

Answer 59

* density increased from gravitational waves and shock waves (supernova) * stars clump up along the wave and orbit center. ("Traffic jam") * we see the leading edge of the waves (blue)

Question 60

Self propagating theory

Answer 60

• stars give rise to additional wave -> shock waves form supernova explosions to shape spiral pattern • our Orion star can be seen this way

Question 61

Transient Spiral Theory

Answer 61

* constantly moving. Arms appear and disappear * young, blue stars * put Galaxy is an example of this

Question 62

Keplers 2nd law says...

Answer 62

The closer to the center the faster Itl swim

Question 63

Our black hole is on a ____ diet. It takes on how many earth sizes a year?

Answer 63

Our black hole is on a starvation diet. It takes in 1/10 of an earth a year

Question 64

MACHOS

Answer 64

Massive astrophysical compact halo objects

Question 65

WIMPS

Answer 65

Weakly interacting massive particles

Question 66

The Milky Way is this shape

Answer 66

Spiral Barg Galaxy

Question 67

In the interior of the Galaxy rotates faster than the exterior, this is known as what?

Answer 67

Differential rotation

Question 68

Which one of keplers laws calculates the mass of the Galaxy?

Answer 68

3

Question 69

Found in the halo and contain the oldest stars of the Galaxy

Answer 69

Globular cluster

Question 70

____ stars are those stars that periodically change in brightness

Answer 70

Variable

Question 71

____ pulsating variables are intrinsic variables that VARY in brightness in a fixed period or span of time

Answer 71

Pulsating

Question 72

2 types of pulsating variable stars

Answer 72

RR Lyrae | Cepheid

Question 73

(T/F) dark matter is thought to be made out of objects that cannot be readily seen, brown and faint red dwarfs, collectively known as MACHOS

Answer 73

True

Question 74

(T/F) anything not classified as MACHO is known as a WIMP

Answer 74

True

Question 75

(T/F) The galactic disk is 20 parsecs across

Answer 75

False

Question 76

(T/F) Our sun is 8 kpc from the center

Answer 76

True

Question 77

(T/F) variable stars can change their size by changing their brightness

Answer 77

False

Question 78

(T/F) The galactic halo contains almost no gas and dust

Answer 78

True

Question 79

(T/F) The galactic disc is where most of the stars are being created

Answer 79

True

Question 80

This is where most of the stars are being created

Answer 80

The galactic bulge