SUN
What type of star is the Sun?
A main sequence star
What process powers the Sun?
Nuclear fusion
What does the HR diagram compare?
Temperature and luminosity
What does EM stand for?
Electromagnetic
What dark feature appears on the Sun’s surface?
Sunspots
What element is most abundant in the Sun?
Hydrogen
What two elements fuse together in the Sun?
Hydrogen → Helium
Where are the hottest stars found on the HR diagram?
Upper left
Which type of spectrum shows bright colored lines?
Emission spectrum
What causes sunspots to appear dark?
Strong magnetic fields
How does energy move from the Sun’s core to its surface?
Radiation and convection
How is nuclear fusion different from combustion?
Fusion changes the nucleus of an atom; combustion is a chemical reaction that occurs in the electron of an atom
Where are red giants located on the HR diagram?
Upper right
Which EM wave has the longest wavelength?
Radio waves
What is released during a solar flare?
Energy and charged particles
How does redshift or blueshift help scientists determine whether the Sun or other stars are moving toward or away from Earth?
Redshift shows an object is moving away from Earth, while blueshift shows it is moving toward Earth.
Why does fusion release so much energy?
A small amount of mass is converted into energy
How does luminosity change as stars move off the main sequence?
Luminosity increases as stars leave the main sequence
What spectrum shows dark lines when light passes through a cooler gas?
An absorption spectrum
How do solar flares affect Earth?
Can disrupt satellites, GPS, and power grids
Why will the Sun never become a supernova?
It is not massive enough
Why can nuclear fusion not happen naturally on Earth like it does in the Sun?
Earth does not have enough pressure or temperature
How can a star’s position on the HR diagram predict its life stage?
Position shows size, temperature, and stage of life
Why are emission spectra useful for identifying elements?
Each element has a unique spectral fingerprint
How do solar maximum and minimum differ in sunspot activity?
Solar maximum has many sunspots; solar minimum has few