M<0.08 .08<M<0.4 0.4<M<1.4 1.4<M<~4 M>~4 P R O T O S T A R | M a i n S e q u e n c e
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M<0.08 .08<M<0.4 0.4<M<1.4 1.4<M<~4 M>~4
P R O T O S T A R
| M a i n S e q u e n c e
| R E D G I A N T
| | | Planetary Supernova
| | | Nebula |
| W h i t e D w a r f |
B r o w n D w a rf Neutron Star OR
Black HoleStellar Evolution
M A I N S E Q U E N C E
R E D G I A N T
W H I T E D W A R F
B R O W N D W A R F
Hubble image of gas and dust 1.4<M<~4 M>~4
around a cluster of young,
Fig. 12-1, p.248
Protostar – contracting gas due to gravity. 1.4<M<~4 M>~4
Size ~ 1 ly ~ 1013 km, energy source -- gravity.
Main Sequence – normal star.
Size ~ 106 km to 107 km, Energy – nuclear fusion
4H He + energy. 0.7% of mass converted to
energy, E = mc². Energy source – nuclear fusion.
Next stage – red giant. Size ~100 times Main Sequence. If not enough mass then Brown Dwarf. Energy source – nuclear fusion.Stellar Evolution
Fig. 12-2a, p.248 1.4<M<~4 M>~4
Main sequence stars 1.4<M<~4 M>~4
Fig. 12-2b, p.248
Fig. 12-4, p.250 1.4<M<~4 M>~4
HST Protostar with two jets 1.4<M<~4 M>~4
Fig. 12-5a, p.251
Protostar with Jet 1.4<M<~4 M>~4
Fig. 12-5b, p.251
Protostar with two jets 1.4<M<~4 M>~4
Fig. 12-5c, p.251
Mass of He is 1.4<M<~4 M>~4
less than 4 H.
energy E = mc².
Fig. 12-6, p.252
Fig. 12-8, p.253 1.4<M<~4 M>~4
Proton - proton chain fusion in main Sequence stars. 1.4<M<~4 M>~4
Does not occur in one step. Also emit photon (γ) and neutrino (ν).
Fig. 12-10, p.255
Hydrostatic 1.4<M<~4 M>~4
in a main
Brown dwarf 1.4<M<~4 M>~4
If protostar does
not have enough
mass to start
star contracts to
Fig. 12-11b, p.256
ν 1.4<M<~4 M>~4 hardly interacts, so it escapes and reaches Earth with the velocity of light or in about 8 minutes.
Since ν hardly interacts, ν detectors need to be extremely large.
Solar neutrino problem pre 2000 – there are not enough neutrinos to account for the energy of the Sun.
Problem solved, ν has a very small mass.Solar Neutrinos (ν)
Homestake 1.4<M<~4 M>~4
Fig. 12-12, p.256
Water detector for 1.4<M<~4 M>~4
neutrinos (ν) in
Fig. 12-13, p.257
Sudbury 1.4<M<~4 M>~4
Fig. 12-14, p.258
Note: Planetary 1.4<M<~4 M>~4
nebula are NOT
Fig. 12-15, p.258