Section 1. The Sun Flashcards
(21 cards)
What is the effective temperature of the Sun?
5780K
What type of star is the Sun?
G2V
What is the equation for luminosity?
L=4πR2σT4
What causes interior convection in the Sun?
Surface granulation
What are sunspots?
Cooler regions of enhanced magnetic fields
What is the approximation for the global magnetic field of the Sun?
A dipole
How is the magnetic field of the Sun generated?
By magnetic dynamos
Requires bulk shearing flow in a conductory medium
Where does shearing flow from in the Sun?
Differential rotation and tachocline
What is the solar atmosphere?
An extended atmosphere visible during eclipse, corona, with light scattering
What is the photosphere?
Where the sun transitions from optically thick to optically thin
What force confines the plasma?
Lorentz force
What is the period of the solar magnetic activity?
An 11 year cycle
What is a solar wind?
An ion tails of comets
Can also erode planet atmosphere
What is the mass loss rate of the Sun?
3*10-14 solar masses per year
What is the equation for angular momentum?
J=mvr
Why is the sun a slow rotator?
Significant magnetic breaking arises due to the angular momentum
J/m α r2
What causes the drive of solar flares?
Magnetic reconnection
What is a solar flare?
A sudden release of magnetic energy
Causes emission in x-rays and radio and optical
What are coronal mass ejections?
Come from solar flares
Causes space weather at Earth and erode planetary atmosphere
What is Helioseismology?
The study of solar oscillations to investigate the internal strucutre and properties of the Sun
What is surface granulation?
Patterns of light areas surrounded by darker borders
