Stars/Composition of Stars
The two most abundant elements in stars are...
Hydrogen and Helium.
the brightness of a star depends on....
size, temperature, luminosity
The universe is...
finite and expanding
Light emitted from a star or galaxy can be separated into a band of colors, called...
a spectrum
How is the Doppler effect used in cosmology?
observe changes in light wavelengths - redshift/blueshift
When two atoms band together to make one heavier atom. The process releases large amounts of energy.
Nuclear Fusion.
Apparent Magnitude is...
how bright is a star when viewed from Earth. A vary large, hot star could look dim just because it is so far away. (how bright we see it)
A singularity is
an incredibly hot, infinitely dense speck of matter
How is a redshift similar to a police car driving by?
The farther away the police car gets the longer the sound waves. The farther away a galaxy gets the longer the light waves.
If sound/light waves are close together ________ frequency
high frequency
Scientists determine the composition of stars by...
studying the visible spectrum of light that comes from a star.
Absolute Magnitude is...
the amount of light that is actually given off by a star. (how bright it actually is)
How old is the Universe?
13.8 billion years old
Think of it in sound terms, red colors are low notes and blue colors are...
high notes
If sound/light waves are farther apart _____ frequency
low frequency
What is a spectroscope
a spectroscope breaks light apart and shows the wavelength of the light.
Light Year is...
the distance that light can travel in one year. 5,865,696,000,000 miles.
Edwin Hubble discovered an electromagnetic property called Red Shift in 1929. What is redshift?
When the wavelength of the light is stretched, so the light is seen as 'shifted' towards the red part of the visible spectrum.
Space is actually expanding causing the...
galaxies to move with it.
Redshift supports...
the Big Bang Theory because it provides evidence that the universe is expanding
Order the colors hottest to coldest.
blue, white, yellow, orange, and red.
Astronomical Unit is...
the distance between the sun and the earth (93 million miles)
The second most abundant element in the universe
Helium
What lead Hubble to conclude that the galaxies are moving apart from each other?
Doppler Effect - changes in light wavelengths
What is the Doppler Effect?
the change in frequency of a wave in relation to an observer who is moving relative to the wave source