Lecture 4 Flashcards Preview

AST205 > Lecture 4 > Flashcards

Flashcards in Lecture 4 Deck (31):
1

WHat is the closest star to the sun?

Proxima Centauri

2

What binary star is Proxima Cen associated with?

Alpha Centauri

3

Could the new planet Proxima b have life?

Potentially, it could support liquid water and has an 11.2 day orbit; it is within the habitable zone but almost too close in

4

What is FAP?

False Alarm Probability -- below 1% is considered probable

5

How did they discover Prox b?

They took data for 16 years, measured the signature of the planet using a spectrograph

6

What does a spectrograph do?

It shows that stars move due to planets, causing a slight red or blue shift

7

Who proposed the idea of atoms?

Democritus

8

Who contributed to the atomic model?

Democritus, Dalton, Brown, Einstein, Perrin

9

Who proposed the plum pudding model?

Thomson

10

What was Rutherford's experiment and what did it prove?

Gold foil, proved that there are nuclei

11

What did Bohr add to the electron theory?

That they were quantized

12

What did de Broglie and Schrodinger discover?

That electrons were both particles and waves

13

What are the three types of spectra?

Emission, Continuous, Absorption

14

What is a continuous spectrum?

Object emits all wavelengths

15

What is an emission spectrum?

Object emits only certain wavelengths (e.g. a thin gas with a temperature)

16

What is an absorption spectrum?

Object absorbs only certain wavelengths (e.g. a thick gas

17

Which part of the spectrum did Herschel discover?

Infrared

18

Which part of the spectrum did Ritter discover?

UV

19

Where is energy stored in atoms?

In the energy levels of the electrons

20

What two types of energy do molecules have?

Rotational and Vibrational

21

Why does thermal radiation occur?

Photos are emitted and absorbed and re-emitted many times over, and distorted by other collisions, thus light of all wavelengths ends up being emitted

22

What is an ideal blackbody?

absorbs all radiation, emits thermal radiation

23

What does the thermal radiation spectrum depend on?

A body's temperature

24

What is Boltzmann's law of thermal radiation?

A hotter object emits more light at ALL wavelengths

25

What is Wien's law of thermal radiation?

A hotter object emits photos of HIGHER average energy

26

What is the ecliptic?

THe path the sun appears to follow across the sky

27

What are the two components of locating a star?

Direction (azimuth) and altitude

28

How does the altitude of the celestial pole relate to your latitude?

They are equivalent

29

What is precession?

The wobble the earth's axis undergoes due to gravity

30

What is synchronous rotation?

Experienced by the moon due to Earth's gravity, the reason why we see the same face of the moon

31

What can blue shift and red shift allow us to detect?

Whether an object is coming towards / going away from us, whether an object is rotating