How do astronomers measure the speed of stars within a galaxy?
Answer
By observing Doppler shifts in emitted light
Astronomers use the Doppler effect; light from stars moving away shows a redshift, and light from stars moving toward them shows a blueshift, allowing measurement of orbital velocity.
#Videos
The Fastest Spinning Galaxy | Space is Weird - YouTube
Related Questions
How do astronomers measure the speed of stars within a galaxy?What is the term for the plot correlating orbital velocity against distance from the galactic center?What observation contradicts the expected behavior based only on visible matter in spiral galaxies?What is the primary driver of rotational velocity differences observed between spiral galaxies?Approximately how long does it take the Milky Way to complete one full rotation?How much faster than the Milky Way do the most massive galaxies spin?What is the defining feature of galaxies known as 'super-spirals'?What component provides the necessary gravitational anchor for fast-moving outer stars in rapidly spinning galaxies?If visible matter alone held the galaxy together, what would happen to super-spirals?How must the density of the dark matter halo change moving outward to produce a flat rotation curve?What fundamental consistency has been found regarding the intrinsic spin of the vast majority of spiral galaxies?