Astro Definitions Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

1 pc?

A

The distance at which 1AU subtends an angle of 1 arcsecond.

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

1 light year?

A

The distance EM waves travel through a vacuum in one year.

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

Absolute magnitude?

A

The apparent magnitude of an object if it were 10pc away from Earth.

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

Recessional velocity?

A

The speed at which an object is receding from Earth.

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

Red shift?

A

Increase in wavelength due to the relative recessive velocity between observer and source.

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

Black hole?

A

An object whose escape velocity is grater than the speed of light.

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

Dark energy?

A

A type of energy that fills the whole of space, and might explain the accelerating expansion of the universe.

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

Supernova?

A

An object that produces a rapid increase in brightness.

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

Neutron star?

A

Incredibly dense star made up of neutrons formed by the collapse of a red giant with a high core mass.

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

Type 1a supernova?

A

A type of supernova that always has the same peak in absolute magnitude. Often used as standard candles as apparent magnitude can be measured.

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

Event horizon?

A

The boundary of the region around an object in which its escape velocity is greater than c.

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

Quantum efficiency?

A

The proportion of incident photons falling on a light detector that are detected.

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

Quasar?

A

A quasi-stellar object that is thought to be a galactic nucleus centred around a black hole.

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

Doppler effect?

A

The change in frequency and wavelength of a wave for a source moving towards or away from an observer.

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

Intensity =

A

P / 4pi d^2

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

Angle of parallax?

A

Half the angle moved by an object compared to the background stars over a 6 month period, when the earth is at opposite ends of its orbit.