Astrophysics

Question 1

Define a universe

Answer 1

large collection of billions of galaxies

Question 2

Define a galaxy

Answer 2

large collection of billions of stars

Question 3

Which galaxy is our solar system in?

Answer 3

The Milky Way

Question 4

What force keeps planets and moons orbitting ?

Answer 4

gravitational force

Question 5

Moons orbit ….

Answer 5

planets

Question 6

Planets orbit ….

Answer 6

stars

Question 7

Artificial satellites orbit the….

Answer 7

earth

Question 8

Comets orbit the …..

Answer 8

sun

Question 9

The gravitational field strength of an object depends on its …

Answer 9

mass
more massive means larger gravitational field strength

Question 10

Equation: orbital speed =

Answer 10

orbital speed = 2 pi r / T

Question 11

What are the stages of evolution for a star of similar mass to our sun?

Answer 11

Nebula
Main sequence star
Red giant
White Dwarf

Question 12

What are the stages of evolution for a star of bigger in mass than our sun?

Answer 12

Nebula
Giant Main Sequence Star
Large red giant
Supernova
Black hole (neutron star)

Question 13

What do we use to measure the brightness of a star?

Answer 13

Absolute magnitude - measure brightness by comparing stars at a standard distance away

Question 14

Can you draw a Hertzsprung Russel diagram and what is unusual about it’s x axis

Answer 14

temp of star on x axis
brightness on y axis
temp axis runs in the opposite direction

Question 15

What are the main arguments in favour of the big bang theory?

Answer 15

Universe is still expanding, evidence from:
red shift or galaxies and stars
cosmic microwave background radiation

The further away the galaxy, the greater the red shift

Question 16

What is the doppler effect and red shift?

Answer 16

Stars moving away from an observer the apparent frequency of light seen will be lower - shifted to the red end of the spectrum

Question 17

Redshift, doppler equation?

Answer 17