the sun

Question 1

how does sun make energy

Answer 1

fusion

Question 2

where does fusion happen

Answer 2

core

Question 3

how does it happen

Answer 3

• hot
• pressure
• hydrogen becomes helium

Question 4

whats the input of pp chain

Answer 4

4 hydrogens

Question 5

output of pp chain

Answer 5

1 helium + energy

Question 6

how long will sun last

Answer 6

another 5 billion years

Question 7

solar neutrino problem

Answer 7

only detect 1/3 of neutrinos than predictions

by the time they hit earth 2//3 transform into the other types

Question 8

equilibrium

Answer 8

due to fusion there is outward presure of radiation that counters the gravity

Question 9

radiation zone

Answer 9

energy transported from core to convection zone using radiation

Question 10

convection zone

Answer 10

energy moved through air convection to surface

Question 11

bright spots on sun

Answer 11

hot gas is rising

Question 12

why is corona so hot

Answer 12

mag field

Question 13

what are sun spots

Answer 13

due to mag flux, cool spots

Question 14

parallax

Answer 14

• to measure distance to objects
• aparent shift of location

Question 15

temp of hottest stars

Answer 15

50000k

Question 16

temp of coolest stars

Answer 16

3000k

Question 17

how to measure mass of binary

Answer 17

2 out of 3:
- period
- speration of orbit
- velocity

Question 18

mass range of stars

Answer 18

0.08Msun to 150Msun

Question 19

size on HR

Answer 19

top right is largest, bottom left is smallest

Question 20

lifetimes on HR

Answer 20

shortest lifetime is top left, longest is bottom right

Question 21

mass on HR

Answer 21

hotter = more mass

Question 22

why does high mass = short life

Answer 22

burns fuel faster

Question 23

props for high mass

Answer 23

• bright
• blue
• short life
• large radius

Question 24

how is a giant or super giant created

Answer 24

when star burns all its fuel

Question 25

open star cluster

Answer 25

- few thousand stars - young - in disk of our galaxy - 10s of lt-yr across

Question 26

globular clusters

Answer 26

million stars very old found in halo

Question 27

composition of interstellar medium

Answer 27

- hydrogen - helium - dust

Question 28

molecular clouds

Answer 28

- cold - dense - hydrogen - dust

Question 29

interstellar extinction

Answer 29

dust blocks view of stars

Question 30

interstellar redding

Answer 30

dust allows IR to pass

Question 31

how does a star form

Answer 31

grav collapse of molecular cloud, by overcoming force of thermal pressure

Question 32

what stabalizes a molecular cloud

Answer 32

- turbulent motion - mag fields - thermal pressure

Question 33

where did the first stars come from

Answer 33

formed with only H and He

Question 34

what is the primary coolent in the early universe

Answer 34

- molecular hydrogen - only at high temps - so only massive stars are formed

Question 35

what is a protostar

Answer 35

- when the cloud gets too dense for light to escape. it stops cooling and heats up. it stops collaping - hot clump formed inside cloud - no fusion

Question 36

what are the jets that shoot from protostar

Answer 36

- out of the rotation axis - high speed gas - maybe created by mag field

Question 37

steps of star evolution

Answer 37

1. protostar forms from cloud 2. it shrinks and heats up as it converts grav potential to heat 3. when its hot enough fusion can become the energy maker 4. fusion inc until it balences

Question 38

what is brown dwarfs

Answer 38

- failed star - not big enough for fusion to start - degeneracy pressure halts contraction - emits IR - luminosity gradually declines

Question 39

distribution of masses of stars

Answer 39

lots of low mass, few high mass

Question 40

what mass is a low mass star

Answer 40

2 Solar mass

Question 41

what mass is intermediate mass star

Answer 41

2 - 8 S mass

Question 42

high mass

Answer 42

8+ S mass

Question 43

evolution for small mass (red dwarf)

Answer 43

straight to white dwarf

Question 44

evoution for sun like stars

Answer 44

giant -> white dwarf

Question 45

evolution for high mass star

Answer 45

supernova explosion to neutron star or black hole

Question 46

how is giant formed

Answer 46

hydrogen is gone, grav collapses, and it heats up pushes outer layer outwards star gets bigger and brighter