Stars

a wave traveling disturbace that moves energy without moving mass

Number of times wave repeats its self per second.

1. 400 nm to 700 nm

Oncoming is shorter, outgoing is longer

Wave goes towards person blue shifted and shorter. Wave goes away longer and red shifted.

All waves length that are present and how much are present at each wave length.

1.More likely to scatter shorter wave lengths.

2.Blue light will scatter 60x more than red light.

3.Person behind equals unscatter, People below equals scatter.

• 1.All marco objects omit this
• 2.Depends on temp, energy emitted at wave lengths
• 3.Temp goes up more light is emitted at shorter wave lengths.

Total energy emitted.

Temp and area.

Absorbs gas at particular wave lengths

True.

• 1.Broading effect.
• 2.Light towards you would be blue shifted.
• 3.Blurred broading wave.

Has nuclear fusion going on helium adam changed to hydrogen adams.

• 1.Size of the star.
• 2.Classified stars into six brightness classes.
• 3.Each step 2.5 brightness coming to your eyes.

False

True

O, B, A, F, G, K, M

Spectral Sequence

L=(alpha)Area x temperature to the fourth

true

• Luminosity=Brightness
• (4)(pie)(distance squared)

• 1. surface area
• 2. distance stellar parallax
• 3. temperature spectral type
• 4. luminosity absolute magnitude
• 5. chemical composition
• 6. brightness
• 7. radial veolcity

• Brightness and distance
• Mass is.

• 1. Tell us mass.
• 2. Pair of stars that orbit each other.
• 3. gravitionally bound together

Same direction but very long distance apart and are not bound

2 nuclei form 1 nucleus and create lots of energy. This needs high temperature, high density, and high speed to happen.

• 1. 10% of observed mass of galaxy
• 2. very low dense
• 3. mostly hydrogen

dark dense regions where stars are formed

beginning of a star's life

main sequence lifetime ( high mass stars spend less time.)

• 1. Helium core shutdown
• 2. rapid collaspe hydrogen fusion
• 3. heat from envelope expands and cools
• 4. core collapses until heluim gets dense enough and hot enough to fuse

less than 2 solar masses that lets fusion reaction runaway and very exotic

True

Method of determing a star's distance from Earth by measuring its surface temperature, luminosity, and apparent magnitude.

Planetlike bodies with less than 0.08 solar massthat cannot sustain fusion in their cores.

low mass main sequence star

• Stellar evolution is the sequence of changes in the
• characteristics of a star resulting from the physical processes occurring
• within it. It is the physical “life history” of a star

1. Stars may exist for billions of years (e.g. Sun is about 4.5 x 109 years old).

• 2. Humans live for less than 102 years. Meaning
• that humans can observe less than 1/107
• (1 10 millionth) of a star like the Sun’s life.

1. Continuous Spectrum - light like the rainbow

2. Absorption Line Spectrum - dark lines on a continuous spectrum

3. Emission Line Spectrum - mostly dark, no continuity

each element produces its own pattern of spectra lines and with a spectrograph you can see the lines.