Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
What is our average distance from the sun? |
150 million km/1AU |
|
|
What is the radius of the sun? |
700,000 km = 109R(earth) |
|
|
What is the mass of the sun? |
2x10^30kg = 300,000M(earth) |
|
|
What is the average density of the sun? |
1.4g/cm^3 |
|
|
What is the luminosity of then sun? |
4x10^26 watts |
|
|
What is the surface temperature of the sun? |
6000K |
|
|
What is the chemical composition of the sun (as well as most other main sequence stars)? |
73% H, 25% He, and 2% all other elements. |
|
|
What is the photosphere? |
The visible spectrum of the sun. The thickness is about 500km (the thinnest layer of the sun). |
|
|
What do sunspots look like? |
They are dark spots on the surface of the sun that are cooler (recall Stefan-Boltzmann's law: L is proportionate to T^4) |
|
|
What is the solar atmosphere composed of? |
The chromosphere and the corona. |
|
|
What are the properties of the chromosphere? |
-lower atmosphere -thickness of 2000km -colour is purple from H-alpha emission lines -temperature changes from 6000K to 20,000K |
|
|
What are the properties of the corona? |
-outer atmosphere -very low in density but very hot -> about 1 million K |
|
|
What is hydrostatic equilibrium? |
The outward push of pressure balancing the inward pull of gravity in a star. |
|
|
How much mass is the sun losing every second? |
4.4x10^9kg/s |
|
|
What is the total mass loss of the sun since it was formed? |
6.4x10^26kg |
|
|
What is the current mass of the sun?? |
2x10^30kg |
|
|
How much % of its current mass has the sun lost? |
0.03% |
|
|
What are the properties of neutrinos? |
No electric charge, no magnetic momentum, and nearly no mass |
|
|
What is the radius of the fusion core of the sun? |
0.3R(sun) |
|
|
What force do neutrinos use to interact with other particles? |
Weak nuclear force. |
|
|
How many neutrinos are emitted by the sun every second? |
1.8x10^38 neutrinos/s |
|
|
How many neutrinos pass through at a distance of 150 million km? |
6.4x10^14 neutrinos/m^2 s |
|
|
Describe a photon's random-walking. |
Photons are constantly scattered by charged particles in random directions. It takes on average a few hundred thousand years for them to move through the radiative zone (0.3R-0.7R[sun]) |
|
|
How is energy transported from 0.7R(sun) to the surface? |
Via convection. Granulation of the sun's surface is a result of this. |
