Stars

Question 1

What is the stellar spectra?

Answer 1

Stars do not have a definite surface. The light we see comes from a layer of gas called the photosphere

Question 2

What is a black body?

Answer 2

A black body is a perfect absorber of radiation. They absorb radiation of any wavelength that falls on it and also radiate all wavelengths too

Question 3

What is intensity?

Answer 3

Power per unit area

Question 4

What is wien’s law?

Answer 4

The wavelength of maximum intensity is inversely proportional to the temperature (double the temperature, half the peak wavelength)

Question 5

What is Stefan’s law?

Answer 5

The intensity of the light at the surface of a star is directly proportional to the fourth power of the surface temperature

Question 6

What is Stefan’s equation?

Answer 6

P = A➰T^4, where A = 4🎵r^2

Question 7

What is the inverse square law?

Answer 7

As you go further from the light source, the light seen striking each square metre each second decreases

Question 8

What Is the inverse square law’s equation?

Answer 8

Intensity = Power / Area

I = 1 / r^2

Question 9

What do you see through visible light multi-wavelength astronomy?

Answer 9

Familiar image

Question 10

Ultra-violet multi-wavelength?

Answer 10

Hotter regions / knots of young giant stars

Question 11

Infra-red?

Answer 11

Heating up of spiral arms / dust lanes

Question 12

X-Ray?

Answer 12

High energy ‘blobs’ / black hole / distant quasars

Question 13

Wavelength of the electro-magnetic spectrum?

Answer 13

Radio.                      x10^3
Micro.                      x10^-2
Infra-Red.               x10^-6
Visible Light.          x10^-7
Ultra-Violet.           x10^-8
X-Rays.                  x10^-10
Gamma Rays.       x10^-12

Question 14

Wavelength of ROYGBIV

Answer 14

R.       Infra-Red 700nm
O.            ⬆️
Y.            ⬆️
G.           ↕️
B.           ⬇️
I.             ⬇️
V.            Ultra-Violet 400nm