Lecture 9

Question 1

whats the evidence for the standard solar model?

Answer 1

• fusion is the only known means of producing enough E
• composition shows that the sun is 76% H and 22% He
• can detect neutrinos from sun

Question 2

describe the solar neutrino problem and solution

Answer 2

problem: a mine detected too few neutrino reactions by ~3
solution: neutrinos oscillate b/w diff flavors

turns out the mine experiment was sensitive to electron neutrinos only. In the sudbury mine, they measured all types of neutrinos which gave the correct predicted rate

Question 3

what is helioseismology?

Answer 3

computer simulation of one mode of vibration of the sun

gives info on solar internal structure

Question 4

what is the sun’s deepest visible region?

describe the gas below this

Answer 4

photosphere

below, gas is opaque (

Question 5

what is the level above the photosphere?

Answer 5

chromosphere

the colored layer, due to H glowing pink

Question 6

what is the level above the chromosphere?

Answer 6

corona

Question 7

what are the cells in the convection zone?

Answer 7

convective cells

Question 8

which is the hottest?

a) photosphere
b) corona
c) chromosphere

what is its max output?

Answer 8

corona (outmost layer)

X rays

Question 9

why is the temp high in the sun’s core?

Answer 9

b/c of gravitational compression

Question 10

temp _____ from core to photosphere

incr or decr?

Answer 10

decr

Question 11

why is the temp high in corona?

Answer 11

magnetic field, which shows light of highly ionized iron atoms

the cooler photosphere appears dark

Question 12

describe sunspots

Answer 12

dark regions on the sun b/c they are cooler than surroundings

they are regions where plasma magnetic field is very strong; deflects hot gas away so it appears cooler