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What does a blue and red shift of absorption lines in a spectrum indicate?
Wiki User
∙ 14y ago
Blue shift is a decrease of a signal's wavelength, and/or an increase in its frequency, due to the Doppler Effect. This indicates that the object is moving towards the observer.
Red shift is the increase of a signal's wavelength, and/or a decrease in its frequency, due to the Doppler Effect. This indicates that the object is moving away from the observer.
Wiki User
∙ 14y ago
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How do you calculate red shift?
The spectrum of light emitted from heated hydrogen has dark lines, caused by the absorption of a very narrow wavelength band of light. These dark lines always take the same location relative to each other. If all the lines in an object's spectrum are shifted by the same amount, towards the red end of the visible spectrum, then the light is "red shifted." The amount of the shift is often described with a number 'z', where z equals the shift in wavelength divided by the wavelength as originally emitted by the object.
Does the velocity of a star toward or away from earth determine measuring the shift of its spectral lines?
Yes. If the star is moving away from the Earth, its spectral lines will shift towards the red end of the spectrum. If it is moving towards the Earth, its spectral lines will shift towards the violet end of the spectrum. This is due to Doppler effect.
Does a redshift spectrum always look red?
No. The red shift simply means that the absorption lines of elements such as hydrogen and helium are shifted towards the red end of the spectrum. A very hot star would normally appear blue. If it were relatively near the earth and so receding relatively slowly, the spectrum would still be blueish, rather than red.
What is important about Hubble's discovery that there is a red shift the spectra of galaxies?
It is difficult to estimate the distance of astronomical objects without information about its intrinsic brightness. However, its spectrum will contain absorption lines based on elements, such as hydrogen and helium, in the outer regions of the object. This lines are characteristic of the elements and they are also red-shifted which allows the red shift to be measured more readily. The red shift is a measure of how fast the object is receding from the earth and, because the red shift is correlated with the distance from the earth, it provides a relatively simple guide to the distance of the object.
What would red shift do to helium's Fraunhofer lines?
The location of those lines would be shifted to a longer wavelength (or lower frequency or energy) -- ie, towards the red part of the visible spectrum. In other words, a red shift.
How do you calculate red shift?
The spectrum of light emitted from heated hydrogen has dark lines, caused by the absorption of a very narrow wavelength band of light. These dark lines always take the same location relative to each other. If all the lines in an object's spectrum are shifted by the same amount, towards the red end of the visible spectrum, then the light is "red shifted." The amount of the shift is often described with a number 'z', where z equals the shift in wavelength divided by the wavelength as originally emitted by the object.
Does the velocity of a star toward or away from earth determine measuring the shift of its spectral lines?
Yes. If the star is moving away from the Earth, its spectral lines will shift towards the red end of the spectrum. If it is moving towards the Earth, its spectral lines will shift towards the violet end of the spectrum. This is due to Doppler effect.
What are the weaknesses of the red shift?
The use of red shift measurements depends on luminosity and the interpretation of the observer. While the spectrum of light must be narrowed down to a single source, one searches for features in the spectrum such as absorption lines, emission lines, or other variations in light intensity. If found, these features can be compared with known features in the spectrum of various chemical compounds found in experiments where that compound is located on earth. Therefore redshifts cannot be calculated by looking at unidentified features whose rest-frame frequency is not known.
Does a redshift spectrum always look red?
No. The red shift simply means that the absorption lines of elements such as hydrogen and helium are shifted towards the red end of the spectrum. A very hot star would normally appear blue. If it were relatively near the earth and so receding relatively slowly, the spectrum would still be blueish, rather than red.
The spectral lines of elements when observed in distant galaxies show a shift towards?
The red end of the spectrum.
Why might scientists mainly astronomers study the color of metals in a flame?
The colours with which an element (metal or other) burns in a flame are the same colours which are absorbed by that element in the sun's spectrum. The colours are very specific to each element and show up as distinct black lines in the solar spectrum. By studying the spectrum it is possible to tell what elements are in the sun [or star] and also their relative abundance.If a star is moving away from us absorption lines are red-shifted [move towards the red end of the spectrum]. The faster the star is moving away, the greater the red-shift. Also, as Hubble discovered, the greater the red-shift, the further away the star is. So the red shift in the absorption spectrum is a measure of not only how fast the star is receding from us but also how far it is. This allows us to tell whether two stars which are apparently in the same direction are actually close together or simply a coincidental alignment of their lines of sight.
What is important about Hubble's discovery that there is a red shift the spectra of galaxies?
It is difficult to estimate the distance of astronomical objects without information about its intrinsic brightness. However, its spectrum will contain absorption lines based on elements, such as hydrogen and helium, in the outer regions of the object. This lines are characteristic of the elements and they are also red-shifted which allows the red shift to be measured more readily. The red shift is a measure of how fast the object is receding from the earth and, because the red shift is correlated with the distance from the earth, it provides a relatively simple guide to the distance of the object.
When the absorption line of a galaxy shift toward the blue end of the spectrum it means that the galaxy is?
It means the heading towards us, red means it is moving away from us.
What would red shift do to helium's Fraunhofer lines?
The location of those lines would be shifted to a longer wavelength (or lower frequency or energy) -- ie, towards the red part of the visible spectrum. In other words, a red shift.
What ''shifts'' when you have a Doppler shift in starlight?
What shifts is the frequencies of the light. This can be observed by certain lines in the spectrum, which have very specific positions (frequencies).
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.
