Astronomy Part 1 Section 2 Flashcards
What is the Lyman Series?
An example of jumps between specific levels in hydrogen atoms. Lyman jumps between level one and other levels
What type of photon is associated with Lyman Series?
Ultraviolet Photons
What is the Balmer Series?
An example of jumps between specific levels in hydrogen atoms. Balmer series jumps between level two and higher levels.
What type of photon is associated with Balmer series?
visual and UV photons
How is an aspectral line produced?
it is produced by many electrons undergoing a particular transition in a particular type of atom
When a source of sound wave approaches an observer, the pitch is higher or lower?
higher
Define the doppler shift
The wavelength of light from a moving source is shifted
Describe what happens to the wavelength when a source is approaching?
Wave crests are closer together, they have a shorter wavelength, a blue shift
Describe what happens to the wavelength when a source is receding?
The wave crests are further apart, the wavelengths are longer, there is a red shift
what is the doppler formula?
V/C = observed wavelength - wavelength at rest/ wavelength at rest
Describe the sun
The sun is a typical star, a self gravitating sphere of hot gas, the sun is middle aged
What percentage of the mass of the solar system is the sun?
> 99%
If halllow, how many earths could the sun hold?
About 10^6 earths
What is Luminosity?
Luminosity is the energy output per time
What is the sun’s luminosity?
Lo = 4 x 10^26
How much does the earth intercept of the sun’s energy output?
10^-9
What is the surface temperature of the sun?
T = 5,800 K
What occurs in the sun’s core?
nuclear fusion
The sun is always in __________ equilibrium
hydrostatic equilibrium
What is hydrostatic equilibrium?
outward gas pressure force balances the inward force of gravity. The sun essentially supports its own weight. the pressure below each layer of the sun must support the weight of that layer plus the weight of the gas above it
What is thermal equilibrium?
energy radiated from the photosphere of sun is replaced by internal energy release
How long could oxidation power the sun?
only for a few thousand years
What does an ionized state mean?
electrons are stripped from the nuclei
Is the gas in the sun in a ionized state?
yes
What is nuclear fusion?
combination of nuclei to produce heavier nuclei with a release of energy
When does fusion occur?
only when the nuclei move fast enough to overcome electrical repulsive force, requires temp > 10^7 K
Describe what and how hydrogen fusion occurs
4 hyrdogen nuclei fuse to form one helium nucleus. 4H —> 1He + energy.
What does einstein’s formula say about hydrogen fusion?
part of the mass is converted to energy
How much of the mass of H is converted to energy?
0.7%
How long can hydrogen fusion power the sun?
For another 5 billion years
What is the constellation Taurus also known as?
“The Bull”
Describe the constellation Taurus
It is high in the south in the evening, nearly overhead. Head has a V shape. The brightest star is Aldebaran which means “the follower”. It follows the Pleiades star cluster in the sky. It is also called “the eye of the bull”, It has a red giant star, it has a faint red binary companion.
according to the standard solar model what is the central density of the sun?
1.6 x 10^5 kg/m^3
How much of the sun’s mass is within the inner half of the radius?
90%
What is the central temperature of the sun?
1.6 x 10^7 or 16 million K
What is the surface temperature of the sun?
5800 K