Astrophysics

Question 1

How does a:

Nebula form

Answer 1

Force of gravity causes clouds of hydrogen nuclei to form into nebulae

Question 2

Why is the:

Colour of a star important

Answer 2

• Colour of a star is directly linked to its surface temperature
• coolest stars glow dull red
• medium like sun orange/yello
• hottest - blue white

Question 3

What is the:

Spectral class groups

Answer 3

OBAFGKM
input sufrace temperature if needed
colour, with mixes, blue - white - yellow - orange - red, no yellow orange or red

Question 4

Why do:

Brighter stars release light waves with different colours?

Answer 4

Visible light with more energy is released which is more blue

Question 5

What is:

Difference between apparent and absolute magntitude

Answer 5

• Apparant magnitude is how bright a star looks when viewed from the earth
• Absolute is when viewed from 32.68 light years, which allows to classify the luminosity equally

Question 6

What is the:

Diagram used to classify stars

Answer 6

Hertzsprung Russell diagram

Question 7

What is strange about the:

Hertzprung Russell diagram

Answer 7

scale multiplied by 2.5
negative values, which are larger than normal values
4 axis (temperature, spectral class, absolute magnitude, luminosity)

Question 8

What is the:

Universe

Answer 8

A collection of billion of galaxies which has billions of stars

Question 9

Difference between:

Orbit of planets and comets

Answer 9

Planets nearly circular, comets eplliptical and moves faster closer to the star orbited

Question 10

What is the:

Steady state theory

Answer 10

Universe always existed and is expanding, with new matter continuoslly created. Only red shift supporting, and countered by law of conservation of energy

Question 11

What is support of:

Big Bang

Answer 11

CMBR, as it is uniform everywhere suggesting universe started from same point
Red shift, all stars are moving away

Question 12

How can:

Electrons be excited

Answer 12

If they absorb exactly enough energy of the next energy level, and need to absorb light waves of an exact frequency

Question 13

What is an:

Absorption spectra?

Answer 13

As the wavelengths released when of light has to go through a gas, some of the wavelengths are absorbed by the gases in the sun, leading to black lines. Absorption spectra would all look the same if all stars were the same distance from Earth, but galaxies have different amount of red shift leading to the graph shifting to the _____

Question 14

LEARN SHAPE OF HERTSPRUNG DIAGRAM

Question 15

WIENS LAW???

Answer 15

Wavenlength of a black body will depend on the temperature of the object