The Sun Flashcards
What is the core temp of the sun?
15 Million Kelvins (MK)
Sun surface temperature?
5800 Kelvin
Radius of the sun compared to earths Radius?
Suns radius is 109 times the earths radius
How old is the sun?
4.6 Billion years
What is the distance between the earth and the sun, also known as unit AU?
1 AU = 1.5 x 10^8 km = 499 light seconds
What does the solar system contain?
The Sun, planets, dwarf planets, asteroids, comets and dust.
Distance between Neptune and the sun
30 AU
Composition of the sun?
74% Hydrogen, 25% Helium and 1% other elements.
How much mass does the sun have compared to Jupiter?
Suns mass is about 1000 times the mass of Jupiter
What percentage of the solar systems mass does the sun contain?
about 99.8%
Where is the sun hottest and what is the temperature?
Core is the hottest part at 15MK.
Temperature of the photosphere?
5800 K
What does the term ‘light’ or ‘electromagnetic radiation’ encompass?
It covers the entire electromagnetic spectrum, from radio waves to gamma rays.
What is the wavelength for visible light?
400 nm to 700 nm.
How is light analysed in terms of waves?
Light is analysed as travelling in electromagnetic waves with frequency, speed, velocity and amplitude?
What is the equation for lights speed and wavelength?
c=λf, where
𝑐 is the speed of light,
𝜆 is the wavelength, and
𝑓 is the frequency.
What are the main interactions of light?
Emission, absorption, transmission and reflection.
How does the Doppler effect affect light?
Light from a moving source shifts to higher or lower frequencies depending on whether the source is moving towards or away from the observer.
What do different wavelengths of light represent?
Different colours
What do spectra tell us?
Spectra carry information about the light source and the medium the light has passes through
What is a black body?
An idealised object that absorbs all radiation and emits a characteristic continuous thermal spectrum.
What does Wiens Law relate to?
The position of the maximum of the thermal spectrum to the temperature of a body
What does the Stefan-Boltzmann Law describe?
The Flux (power per square meter) emitted by a black body.
What is a photon?
Packet of energy described by quantum mechanics.
How is photon energy related to frequency?
By the equation
E = hf
where h is Plancks constant
What are the 3 types of spectra?
Thermal (continuous), emission (specific lines)
absorption (continuous with dark lines)
