they provide key information about the composition, temperature, and motion of astronomical objects. By analyzing the unique patterns of spectral lines emitted or absorbed by celestial bodies, astronomers can determine their chemical makeup, distinguish between different types of stars, and even measure their radial velocities. This allows scientists to study the properties and evolution of galaxies, stars, and other celestial objects in great detail.
The red shift depends on the relative motion of the emitting source and receiving detector. Hydrogen per se has no red shift. There is hydrogen with great red shift (in stars in galaxies far away that are moving rapidly away from us).
Scientists determined that the object was expanding by analyzing its light spectrum using a spectrograph. By observing the Doppler shift in the spectral lines, scientists could infer the motion of the object relative to Earth, leading to the conclusion that it was moving away and expanding.
The Andromeda galaxy is moving towards our Milky Way galaxy at a speed of about 110 km/s. This relative motion is causing the galaxies to slowly approach each other and will eventually result in a collision in billions of years.
Red shift is the change in the spectra of galaxies towards being more red than we would expect them to be. Doppler Shift results from galaxies being in motion away from us. Thus, the large Andromeda Galaxy has a blue shift, because it and our Milky Way Galaxy are being pulled towards each other due to gravity. Cosmological Shift results from the space between us and other galaxies growing larger over time, even though neither they nor our Milky Way Galaxy are in motion relative to one another.
The method used to determine a star's speed of approach is called "radial velocity." This technique measures the star's motion towards or away from us along the line of sight by analyzing the Doppler shift in its spectral lines. The amount of shift in the spectral lines provides information about the star's speed and direction of motion relative to us.
Relative motion
S. C. Wu has written: 'Ground motion input in seismic evaluation studies' -- subject(s): Earthquake hazard analysis, Spectral sensitivity
Distant galaxies do not rise and set like stars in the sky. Their positions in the sky are fixed relative to our perspective on Earth. The apparent motion of rising and setting is a phenomenon caused by the rotation of our planet.
Friction opposes the relative motion of surfaces in contact. It acts in the direction opposite to the direction of motion or tendency of motion between two surfaces.
Motion is relative to an observer's frame of Reference.
When the wavelength of spectral light emitted from an object increases, it moves towards the red end of the visible light spectrum, also known as the redshift. This indicates that the object is moving away from Earth.
At rest and in motion are relative terms. When we say 'in motion' or 'at rest' we mean relative to something else. If you were travelling in a car for instance, you would be at rest relative to the car but in motion relative to the outside world.
Nearby galaxies won't show much of a redshift, because they aren't moving away very quickly - or at all. For example, the Andromeda Galaxy, M31, is actually getting closer - and will collide with the Milky Way in about 3 billion years.
Peculiar velocities are the individual speeds at which galaxies move within the universe, separate from the overall expansion of the universe. They differ from the general motion of galaxies because they are influenced by local gravitational interactions between galaxies.
If the wavelength decreases, the spectral line moves towards the blue end of the visible light spectrum. This phenomenon is known as blue shift, indicating that the object is moving towards Earth.
motion is realtive