Stellar Spectrum and Sound Waves Quiz

Study Notes

Stellar Spectrum and Spectral Lines

Elements emit unique spectral lines (sets of lines)
Visible lines depend on the element's temperature. Hotter = more spectral lines
Each atom/ion/molecule has a unique spectral fingerprint. This is a specific combination of emission and absorption lines.
White light is a mix of all wavelengths.
Neon light produces an emission spectrum.
Thermal radiation: Hotter objects emit more light at all frequencies, and photons of higher average energy.

Sound and Doppler Shift

Doppler shift in sound: Change in frequency when a sound source moves relative to an observer. Source closer = higher frequency (higher pitch); farther = lower frequency (lower pitch).
Approaching source = shorter wavelengths (higher pitch)
Moving away from source = longer wavelengths (lower pitch)
Redshift: Object moving away
Blueshift: Object moving towards

Stars

OBAFGKM: Temperature classification sequence for stars, hotter (blue) to cooler (red).
O – Hottest
B
A
F
G
K
M – Coolest
Star color defines temperature.
Mass→Gravity→Rate of Fusion→Luminosity →Temperature (MGFLT)
Luminosity = Total energy radiated per second at all wavelengths
Luminosity depends on the star's temperature and size.
Distance to nearby stars measured by parallax.
Larger stars fuse faster, die quicker.
Composition: 70% Hydrogen, 28% Helium, 2% other elements
Fusion requires high temperature & density.
Binary stars orbit each other.
Stars form from nebulae, die in a supernova.
Star evolution: Nebula-->Main Sequence -->Red Super/Giant -->Blue Super/Giant -->White Dwarf
Main sequence = stable stars like our Sun

The Sun

Sun's diameter = 109 times Earth's diameter.
Sun's mass = 333,000 times Earth's mass.
Hydrogen fuses into Helium in the Sun's core (via the proton-proton chain)
Nuclear fusion powers the Sun.
Photons travel through the Sun's interior.
The journey of photons through the Sun is called a random walk.
The trip from the Sun's core to us takes 8 minutes.

Sun's Structure

Inner:*
Core: Location of nuclear fusion, proton-proton chain, gamma ray production. 14-15 million degrees Kelvin
Radiative Zone: Energy transport via radiation, 70% of the sun's radius.
Convective Zone: Energy transport via convection
Outer:*
Photosphere: Visible surface of the Sun, 6000 degrees Kelvin, Sunspots located.
Chromosphere: Layer above the photosphere, hotter than the photosphere, where sunspots are located.
Corona: Outermost layer, much hotter than the photosphere, source of the solar wind.
Solar Flares: Occur in the corona

Atomic Structure

Atom: Fundamental building block of matter, consists of a nucleus (protons, neutrons )and electrons
Ground state: Electron's lowest energy level.
Excited State: Electron's higher energy level.
Ionized: Atom with missing electrons
Number of protons defines the element.
Neutrals atoms, have the same number of protons and electrons.
Isotopes: Atoms with the same number of protons but different numbers of neutrons.

Description

Test your knowledge on stellar spectrum, spectral lines, and the Doppler effect in sound. This quiz covers the unique spectral fingerprints of elements, temperature classification of stars, and the relationship between sound frequency and the movement of sources. Challenge yourself with these concepts from physics and astronomy!