- Redshift and Hubbles Law - NASA
The amount of departure, and the type, depends on the value of the total mass of the universe In this way a plot of recession velocity (or redshift) vs distance, which is a straight line at small distances, can tell us about the total amount of matter in the universe and may provide crucial information about the mysterious dark matter
- NASA
They're light years away, man, and that's pretty far (lightspeed's the limit, the big speed limit) But there's plenty we can learn from the light of a star (split it with a prism, there's little lines in it) By looking at the spectrum at the light that's glowing (wavelengths of emission, measured with precision) Its Doppler Shift will tell us if it's coming or going Doo doo doo doo doo-ooo
- StarChild: A Learning Center for Young Astronomers
When a star is approaching and it's coming our way Its spectrum seems bluer, won't you hear what I say And when a star's retreating way out of range And the scientist measures its frequency change Well that's a redshift, redshift If the star is moving away By reading Doppler Shifts of all we see in the skies (clusters of galaxies, near and far) We get the big picture and a big surprise
- Parallax - NASA
Parallax Astronomers derive distances to the nearest stars (closer than about 100 light-years) by a method called stellar parallax
- NGC 253, a starburst galaxy - NASA
NGC 253, a starburst galaxy On the left, you see an image of the spiral galaxy NGC 253, taken with a ground-based telescope
- StarChild: The Universe - NASA
The universe is a vast expanse of space which contains all of the matter and energy in existence The universe contains all of the galaxies, stars, and planets
- StarChild: Cosmology - NASA
Will it expand forever, expand to a certain size and stop, or will it stop and begin to collapse? Data suggesting that the universe is expanding at an accelerating rate were published in 1998 For more than ten years astronomers studied the expansion of the universe by measuring the redshift and brightness of distant supernovae
- Supernovae - NASA
Supernovae At large distances (up to about 1 billion light-years), astronomers can no longer use methods such as parallax or Cepheid variables
|