Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Astronomy > Unit 6 > Flashcards

Unit 6 Flashcards

1
Q

Galaxy

A

a large group of stars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Average galaxy size

A

100 billion stars, 100,000 light years in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

galacitic disk

A

center of galaxy and flat disk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

globular cluster

A

stars orbiting the galactic center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

interstellar dust

A

obscures our view of the galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

radio waves help us what

A

map out the galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How fast is the Sun revolving around the center of the Galaxy?

A

500,000 mi/hr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of radiation can penetrate the dust clouds of our Galaxy, allowing us to see the spiral structure? (It is also known as 21 cm hydrogen radiation.)

A

radio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

cepheid variable star

A

gets brighter and dimmer in a regular pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Henrietta Leavitt

A

figured out the pattern that relates to luminosity and cepheid variable stars, this allows us to find distance of stars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Distant indicator and millions of light years

A

cepheid variables 15-20 ly, red supergiants 50 ly, blue supergiants 80 ly, Novae 80 ly, globular clusters 130 ly, supernovae 8,000 ly, brightest galaxy in cluster 15,000 ly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What two properties of a Cepheid variable star do we need to know in order to calculate the approximate distance from Earth?

A

apparent magnitude
luminosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What two properties of a Cepheid variable star do we need to know in order to calculate the approximate distance from Earth?

A

apparent magnitude
luminosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

types of galaxies

A

spiral, barred spiral, ellipticals, irregulars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

spiral

A

Sa, Sb, Sc, (a is tightly wrapped) SBa, SBb, SBc (B means barred)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ellipticals

A

look like circles, E0-E7 (0 is more circular and 7 is more oval)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

irregulars

A

any other type of galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

clusters

A

groups of galaxies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

dark matter

A

matter we are unable to observe from Earth

20
Q

quasars

A

100 times brighter than average galaxy, very far away

21
Q

Who developed a classification system for galaxies?

A

Edwin Hubble

22
Q

black hole

A

so strong gravity that light can’t escape

23
Q

escape velocity

A

how fast something must go to escape an objects gravity (shrink something and it has a higher escape velocity)

24
Q

event horizon

A

boundary of black hole

25
Q

active galaxies

A

brightness between normal galaxy and quasar

26
Q

galactic nuclei

A

bright starlike, called seyfert galaxies

27
Q

capricornus

A

the goat, shaped like a big upside down triangle, no bright stars

28
Q

libra

A

themis, shaped like a trapazoid, no bright star

29
Q

scorpius

A

the scorpion, shaped like a curved hook, bright star Antares

30
Q

sagittarius

A

the archer, shaped like someone with a bow, no bright star

31
Q

Observing a significant wobble in a star’s orbit would suggest what possibility (if no binary star is visible)?

A

Its companion star became a black hole.

32
Q

t/f Cepheid variables are useful for determining the distances to some galaxies.

A

true

33
Q

t/f Earth is near the center of the Milky Way Galaxy.

A

false

34
Q

Edwin Hubble’s discovery of a Cepheid variable in the Andromeda nebula led him to conclude that the nebula was what?

A

a distant galaxy

35
Q

Who developed a classification system for galaxies?

A

Edwin Hubble

36
Q

Henrietta Leavitt found that the brighter appearing Cepheids always had longer periods of light variation. This is an expression of what?

A

period-luminosity relation

37
Q

If the Sun were to become a black hole, what would happen to Earth?

A

It would continue in the same orbit.

38
Q

How long does it take the Sun to revolve around the center of the galaxy?

A

two hundred million years

39
Q

Our sun is a member of which galaxy?

A

Milky Way

40
Q

Which type of radiation helped us map the galaxy?

A

21 cm radio waves

41
Q

What is the surface or boundary of a black hole called?

A

event horizon

42
Q

The Local Group contains

A

twenty-four galaxies

43
Q

t/f Quasars appear to be among the most distant objects known in the universe.

A

true

44
Q

What is believed to be at the center of most galaxies?

A

black holes

45
Q

t/f It would be impossible to orbit a black hole, because you would always be sucked in.

A

false

Astronomy (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions