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How does the speed of the star affect the spectrum?
The speed of a star affects its spectrum through the Doppler effect. If a star is moving towards or away from us, the wavelengths of the light it emits will be shifted towards the blue (blue shift) or red (red shift) end of the spectrum, respectively. This shift can provide information about the star's velocity and direction of motion.
What is a Doppler red shift and a Doppler blue shift?
A Doppler red-shift is a shift in recognizable features of a star's spectrum from the wavelengths where we know they belong toward longer wavelengths. Such a shift can be caused by the star's moving away from us, and that's how it's interpreted when astronomers see it. A Doppler blue-shift is a shift in recognizable features of a star's spectrum from the wavelengths where we know they belong toward shorter wavelengths. Such a shift can be caused by the star's moving toward us, and that's how it's interpreted when astronomers see it.
What can you infer about a star that exhibits a red shift in its spectra?
A red shift in a star's spectrum indicates that the star is moving away from us. This is due to the Doppler effect, where the wavelength of light is stretched as the source moves away, shifting it towards the red end of the spectrum. This can be used to determine the star's velocity and direction of movement.
What is a red shift and what does it mean for a star?
It's a change (decrease) in the frequency of the light we receive from the star. Equivalently, an increase in the wavelength. It usually means the star is moving away from us, though it might also be caused (usually to a lesser extent) by the star's gravitation.
What is an effect called in which a star or galaxy appears to move away from an observer?
red shift
What is an area that's not currently being studied?
Hubble's red shift is due to movement, however, a large mass (star) will gravitationally cause a red shift. The former is studied; the latter is not.
What turns red in the red shift?
light is put into a spectrum from red to blue. red shift is when a star is moving away from us so fast that the light waves stretch moving it up the spectrum, so up towards infared
What does a red shift tell astronomers about stars or galaxies?
A red shift in the light emitted by a star or galaxy indicates that it is moving away from us. By measuring the amount of red shift, astronomers can determine the speed at which the object is receding and use this information to study the expansion of the universe and the distance to the object.
What the difference between red shift and blue shift?
The frequency of light from a star is reduced (its wavelength increased) when the star is moving away from the observer. Red light has longer wavelengths than blue light. So the light from a star which is moving away from the earth appears to be redder than it actually was. This phenomenon is similar to the pitch of an ambulance siren dropping as it passes you and is moving away. The true spectrum for light from a star depends on the temperature of the star, but there are characteristic absorption lines (dark lines) in the spectrum which are specific to chemical elements which are present in the outer regions of the stars - such as hydrogen and helium. Light from within the star is absorbed by the atoms of these elements when they move from a low-energy state to one with a higher energy level. A comparison of where in the spectrum these lines appear to be against where they should be (for a stationary) star are a measure of the red-shift (or blue shift).A red shift is observed if an object is moving away from the earth while a blue shift is observed if it is approaching the earth.
What are the difference between red shift and blue shift?
The frequency of light from a star is reduced (its wavelength increased) when the star is moving away from the observer. Red light has longer wavelengths than blue light. So the light from a star which is moving away from the earth appears to be redder than it actually was. This phenomenon is similar to the pitch of an ambulance siren dropping as it passes you and is moving away. The true spectrum for light from a star depends on the temperature of the star, but there are characteristic absorption lines (dark lines) in the spectrum which are specific to chemical elements which are present in the outer regions of the stars - such as hydrogen and helium. Light from within the star is absorbed by the atoms of these elements when they move from a low-energy state to one with a higher energy level. A comparison of where in the spectrum these lines appear to be against where they should be (for a stationary) star are a measure of the red-shift (or blue shift).A red shift is observed if an object is moving away from the earth while a blue shift is observed if it is approaching the earth.
What does the red shift tell scientists?
The redshift tells scientists how fast a star or galaxy is moving away from us.
How does someone know the universe is 14.2 billion light years long if it goes on forever?
This was one of the major contributions of Astronomer Hubble (and others). The 'red shift' of light is an easily proved phenomenon - analogous to Doppler shift of frequency. And, the further away a star is, the greater its red shift. The red shift is caused by the speed at which the distant star is retreating. AND, when those two facts are combined, we can see that the universe appears to have expanded from a point. And the time back to that point in time is a constant irrespective of which star is studied. So we have an expanding universe in which the velocity of a star is proportional to its distance. The time back to that common origin is about 14.5 x109 years ago.
