How to measure the tangential component of velocity of receding starsor quasars?

In summary, The tangential component of velocity of receding stars or quasars cannot be measured. While the velocity determined by observing the red shift only gives the radial component, proper motion can be measured for stars through various methods such as comparing images from different epochs or using interferometry. However, measuring the proper motion of quasars is currently not feasible due to their immense distance.
  • #1
aniketp
84
0
Hi all,
How to measure the tangential component of velocity of receding starsor quasars?
I ask this because i think the velocity determined by observing the red shift will give only the radial component...won't
Thnx for replying...
 
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  • #2
You can't.
 
  • #3
For stars their proper motion (not just radial) can be measured a few ways. If they move fast enough, comparing images from different epochs and looking for a change in position works. Interferometry, if high enough resolution, can also be used to measure the proper motion of stars. As for Quasars, I would say with current technology it's virtually impossible as they are much much too far away.
 

1. How is the tangential component of velocity measured for receding stars or quasars?

The tangential component of velocity is measured using a technique called spectroscopy. This involves analyzing the light emitted by the receding star or quasar and looking for changes in the wavelength of specific spectral lines. These changes can indicate the velocity of the object along our line of sight.

2. What equipment is needed to measure the tangential component of velocity for receding stars or quasars?

To measure the tangential component of velocity, scientists use specialized instruments such as spectrographs, which can disperse light into its component wavelengths, and telescopes with high-resolution capabilities. These instruments are often located at observatories or on space-based telescopes.

3. What is the significance of measuring the tangential component of velocity for receding stars or quasars?

Measuring the tangential component of velocity can provide important information about the motion and distance of receding stars and quasars. This data, combined with other measurements, can help us understand the structure and evolution of the universe.

4. How does measuring the tangential component of velocity help us understand the expansion of the universe?

The tangential component of velocity is one of the components used to calculate the overall velocity of receding objects in the universe. This data, along with the object's distance, can be used to calculate the Hubble constant, which is a measure of the rate of expansion of the universe.

5. Are there any challenges or limitations to measuring the tangential component of velocity for receding stars or quasars?

There are several challenges and limitations to measuring the tangential component of velocity, including the effects of cosmic dust and gas on the light emitted by the receding object, the accuracy of distance measurements, and the limitations of current technology. Additionally, the expansion of the universe can cause objects to appear to have a tangential component of velocity even when they are not actually moving tangentially.

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