Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physics > Astrophysics > Flashcards

Astrophysics Flashcards

(61 cards)

Start Studying
1
Q

Universe

A

A large collection of billions of galaxies

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

Galaxies

A

A large collections of billions of starts

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

What are planetary systems

A

Planets and other astronomical objects orbit around a star at the centre

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

Name of our solar system

A

Milky Way galaxy

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

Order of planets in the solar system

A

Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune

My very easy method just speeds up nothing

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

Weight

A

The force acting on an object due to gravitational attraction

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

What affects the gfs of different objects

A

Greater mass = greater gfs

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

How does the value of the gravitational field strength vary on a planet

A

Greater distance = lower gfs

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

What do planets orbit

A

Sun

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

What do moons orbit

A

Planet

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

What do comets orbit

A

Sun

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

What do asteroids orbit

A

Sun

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

What do artificial satellites

A

Earth

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

Similarities in the way planets orbit the sun

A

-all slightly elliptical with the sun in the centre
-orbit in the same plane
-travel in the same direction around the sun

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

Differences in the orbits of planets around the sun

A

-different distances from the sun
-different speeds
-different amounts orbital period

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

How does the speed of orbit vary with orbital distance

A

Higher orbital distance = lower speed

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

Orbit of moons

A

Circular path, some planets have more than one moon

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

Orbital motion of comets

A

-highly elliptical orbit
-speed changes during the orbit (faster nearer the sun)

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

Average orbital speed equation

A

V = (2πr)/T

r = Orbital radius
T = orbital period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is orbital period

A

The time taken for an object to complete one orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What affects the colour stars emit

A

The surface temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Colour of hotter and cooler stars

A

Hotter = blue
Cooler = red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do astronomical objects change temperature with size

A

Cool as they exapand
Heat up as they contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

formation of a main sequence star

A

nebula -> protostar -> main sequence star

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
nebula
giant interstellar cloud of gas and dust
26
protostar
-force of gravity within a nebula pulls the particles close together until a hot ball of gas forms (protostar) -as the particles are pulled closer together the density increases -results in more frequent collisions between the particles, causing the temperature to increase
27
main sequence star
-protostar becomes hot enough, and nuclear fusion reactions occur within its core -it is a main sequence star when fusion starts -the star is in equilibrium and is 'stable' (outward pressure of reactions = inward pressure of gravity)
28
life cycle of a solar mass atar
red giant -> planetary nebula -> white dwarf
29
red giant
-the hydrogen causing the fusion reactions in the star will begin to run out -star collapses under the force of gravity -fusion reactions in the core start to die down -star begins to fuse helium which causes the outer part of the star to expand -as the star expands, its surface cools and becomes a red giant
30
white dwarf
-after helium fusion reactions finish, star collapses and becomes a white dwarf -the white dwarf cools down over time and the amount of energy it emits decreases
31
black dwarf
the white dwarf cools and stops radiating
32
life cycle of larger stars after main sequence star
red supergiant -> supernova -> neutron star (black hole)
33
differences between lower mass and higher mass star
-higher mass star stays on the main sequence for a short time before it becomes a red supergiant -a lower mass star fuses helium into heavy elements like carbon, high mass star is heavier elements like iron
34
red supergiant
same as red giant but bigger
35
supernova
-fusion reactions in the red supergiant cannot continue, the core of the star will collapse and cause a explosion called a supernova -a dense body called a neutron star will form at the centre of this explosion -the outer remnants of the star are ejected into space forming new clouds of dust and gas (nebula) -heaviest elements are formed during a supernova, and are ejected into space
36
neutron star (black hole)
-the neutron star at the centre will continue to collapse under gravity until it forms a black hole -it is a dense point in space that light cannot escape from
37
luminosity
-the total amount of light energy emitted by the star
38
apparent magnitude
the perceived brightness of a star as seen from Earth (lower magnitude is brighter star, one unit of magnitude is 2.5x, compared to a constant)
39
absolute magnitude
a measure of how bright stars would appear if they were all placed the same distance away from the Earth (unit is 10 parsecs, or 32.6 light years from earth)
40
Hertzsprung Russell diagram axes
luminosity on y axis, temperature on the x axis
41
luminosity units on HS diagram
1 luminosity = 1
42
main sequence stars location on the HS disgram
band of stars going from top left (bright and hot) to bottom right (dim and cool)
43
white dwarfs on HS diagram
below the main sequence and slightly to the left, diagonal going from high right to low left
44
red giants on HS diagram
-above the main sequence on the right hand side -connected to the line of main sequence stars -diagonal from low left to high right
45
super giants on HS diagram
top side above the main sequence stars, going from left to right, slight diagonal from high left to low right
46
super giant stars and red dwarfs
main sequence stars -super giant stars are bright, blue and bigger -red dwarfs stars and dimmer, red and smaller
47
class of stars from hot to cold
O, B, A, F, G, K, M
48
class O colours and temp
>33,000 Blue
49
class B colours and temp
blue- 9,000-33,000
50
Class A colours and temp
white 9000
51
class F colours and temp
Yellow- 6,000-9,000
52
Class G colours and temp
Yellow 6,000
53
Class K colours and temp
Orange 3,000-6,000
54
Class M colours and temp
Red 3,000
55
wiens displacement law
Peak lambda x surface temperature = 2.9 x 10 to the -3
56
why can green stars not exist
red, green and blue light is also emitted, which is seen as white light
57
Big bang theory
1. 14bn years ago the universe began from a very small region that was hot and dense 2. there was a giant explosion (Big Bang) 3. the universe expanded from a single point, cooling as it did 4. each point expands away from the others, the further away things are the faster they move
58
main evidence supporting the big bang
1. galactic red-shift 2. cosmic microwave background (CMB) radiation
59
evidence from galactic red shift
-light spectra from supernova show that distant galaxies are receding -the light spectra show that light is redshifted, showing that the universe is expanding
60
how does the distance of a galaxy compared to a point change its relative speed to the point
further away = greater speed
61
evidence from CMB radiation

Physics (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions