Emission spectra is used in the study of stars because when the lines emitted are studied, scientists are able to determine what the star is composed of. The temperature and mass of the star are also determined by the emission spectra.
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∙ 9y agoWiki User
∙ 16y agoThe color spectrum can help astronomers tell if the star is moving closer or away from the earth by using dopler effect. If the color is shifted to the red part of the specturm (over the course of many observations) it means it is moving away. If the color is shifted to the blue or violet part it is moving closer. The same thing happens when you hear a siren go by; as it gets closer it gets louder than fades away the further away get gets. The color spectrum call also tell the astronomer what elements are present in the star. Each element has a unique color signture like a fingerprint. For the purposes of my answer, I will assume that you mean the spectrum of the light that the particular star under consideration is emitting. The spectrum of the starlight is separated into its different colors, or wavelengths, with a spectrometer, which uses a prism or diffraction grating to refract (or diffract) the light into different directions depending on the wavelength. You use photographic film or electronic detectors to measure the intensity of the light at each wavelength.
Recognize that the measured spectrum extends far beyond the visible colors which our eyes can detect. The visible spectrum is typically defined as covering wavelengths from 400 nanometers (blue) to 700 nm (red). Wavelengths shorter than 400 nm are the ultraviolet (then the extreme ultraviolet, then soft X-rays, 'regular' X-rays, etc.) Wavelengths longer than 700 nm are the infrared (then the far infrared, then microwaves, etc.)
A second important aspect of the star's spectrum that you need to know is the spectral shape, which is the graph of energy density vs. wavelength. A good illustration of this is shown on http://en.wikipedia.org/wiki/Planck%27s_law
There are several ways that the spectrum can be used. First off, if you look at the Wikipedia illustration, you see that the spectrum has a different shape for different temperatures. This allows you to tell what the surface temperature of the star is, which can give a good indication of the type of star (white dwarf, red giant, etc).
Second, if you look closely at the spectrum, you see there are wavelength that are very dim or missing entirely. They are very dim because that wavelength is absorbed by a particular atom in the star's outer atmosphere. (Or by dust and molecules that are between us and the star.) Every atom has its own set of wavelengths that it absorbs, so the set of absorption lines (as they are called) lets you figure out what atoms are present in the outer atmosphere. Hydrogen and helium are common. When you start seeing heavier materials, like carbon, sodium or silicon, then you know the star is old and nearing the end of its life.
Third, you can tell how far away the star is from the earth. Because the universe is expanding, all the stars (except a few that are close to us) are moving away from us. The further away they are, the faster they are moving away. This is known as "Hubble's Law", after Edwin Hubble who published it in 1929. (For more on this, see the Wikipedia article at http://en.wikipedia.org/wiki/Hubble%27s_law.)
One of the results of Einstein's theory of (Special) Relativity is that an object that emits light and is moving away from you looks redder (longer wavelengths) than the same object would if it were not moving. (This is called the Doppler shift, or red shift.) The amount of the shift depends upon the speed at which the object is moving. Once you have measured the spectrum, you can determine how much the spectrum is red-shifted, which tells you how fast the star is moving, which in turn tells how far away the star is.
-Dr.RSJameson 26-Feb-2008
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∙ 10y agoThe absorption lines in a star's spectrum tell us many things about the star, including its chemical composition (from which lines appear) and its speed toward or away from us (from the Doppler shift of those lines).
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∙ 13y agoThe emission spectra can tell us the atoms of a star and the atoms tell us what the star is made of
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∙ 13y agoBy studying the lines on the spectrum emitted by a star, scientists can determine what elements a star is composed of.
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∙ 12y agoFor this purpose, astronomers would analyze the starlight's spectrum.
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∙ 13y agoEach element leaves a characteristic "signature" in the spectrum - lines at certain places of the spectrum indicate a certain element.
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∙ 13y agothrough a stereoscopy
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∙ 11y agoyes
Enzymes.
Astronomers believe Mercury has a high concentration of iron because it is one of the densest planets in our solar system, suggesting a significant amount of heavy elements.
The amount of an element present does not affect the element's identity. Each element is defined by the number of protons in its nucleus, known as its atomic number. This remains constant regardless of the quantity of the element present.
You still need to know the number of protons present in order to find the atomic mass.
Nitrogen is present in proteins and nucleic acids, but not in sugars and fats.
They detect the absorption lines consistent with hydrogen.
From Encyclopedia we can get a list of famous & not famous astronomers & astronauts of the past & present.
To know the quantity of matter present in the element or a thing
What makes up the star or element.
Astronomers can determine the composition of a distant object by analyzing its spectrum of light. Each element or molecule absorbs and emits light at specific wavelengths, leaving unique signatures in the spectrum. By comparing these signatures to known patterns, astronomers can identify the elements and compounds present in the object.
Elements are present in the periodic table. For example Copper (Cu) is an element but copper sulphate CuSO4 is a compound.... Elements present in copper sulpahte are Copper (Cu),Sulphur (S) and Oxygen (O).
The element "Oxygen".
Mostly by spectrographic observation. Every distinct element radiates exact and specific frequencies of light. By taking a tiny sample of the element and heating it to "glowing hot", we can measure the spectrum of the light that this element gives off. This is how a spectrometer works. In a star, the elements are already at thousands of degrees, so all astronomers need to do is to analyze the spectrum; most stars have spectra that are as distinct as fingerprints to people. We can determine what elements are present, and in what proportions, with considerable accuracy.
Some astronomers are likely to be good at DIY, but most would probably get a contractor in.
Astronomers know because they have studied star patterns and placements and know when there has been a change between where there is a black hole and where there isn't one.
Iron (Fe) is the element present in ferric chloride.
You know how many protons and neutrons are present. You can also figure out what element it is if you happen to have a periodic table of elememts.