How do scientist use diffrent spectra to figure out the composition of astar's outer layer?
826131
Each chemical absorbs a different portion of the light band. The portions that are not absorbed are what give things color. If you're looking at the spectral analysis of a star, you can tell what chemicals are present by the black bands on the light spectrum, which represent absorbed light. If that color is absorbed, then the corresponding chemical must be present.
139895
2 ways come to mind.\n\nYou make a series of solutions of increasing concentration as well as a blank (deionized water) and measure their absorbance in a spectrometer. You find a regression of the data and figure out the methylene blue based on its absorbance.\n\nStandard addition. You take unknown absorbance and add increasing concentrations of methylene blue to it. Graph the data and figure out the concetration corresponding to the y intercetp.
809710
is you mean mass spectroscopy.. try this link...
640432
The Hertzsprung-Russell diagram was developed based on the independent work of the 2 astronomers Henry Norris Russell and Ejnar Hertzsprung in the late 1800s.\n\nThey were investigating the luminosity and spectral class of stars.  The luminosity of a star is the total energy output of the star across all wavelengths (actually the bolometric luminosity).
161934
Optical telescope based information about these bodies largely comes from the frequency spectrum of the light we receive.  Peaks and dips at particular frequencies can identify relative abundance of some of the elements in the star which emit those frequencies, and substances in the light path that absorb specific frequencies.  Frequency shifts of these features indicate velocities.\nOther information comes from distortion of the image due to gravitational "lensing" (bending of the light by objects in the light path).
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http://www.chemicalelements.com/elements/k.html\n\nhttp://www-spof.gsfc.nasa.gov/stargaze/Q6.htm
114334
IR analysis of substances is very easy. You just put a few milligrams of the (solid, liquid, or gas) sample onto the IR cell, scan with IR and you get the output spectra. You use a guide to interpret the spectra. These are available in chemistry books and in the net. With paint, it depends on which component of paint you wish to analyze. Normally each component - pigment, additives, binders, etc - has its own characteristic chemical, and hence functional groups to look out for. If you don't need the solvent, then evaporate it off and analyze the sample you obtained. You can also do some preliminary separation by chromatography, centrifugation, filtration, etc. Paints indeed give color to life!
652676
a. emission lines from reference elemnts on Earth
255650
Yes.  Or at least it can by using deep level optical spectroscopy (DLOS).  See the reference below:
1013647
Read this: http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_postmain.html\n\nThe "onion" layer is because the core contains different layers like an onion.
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this ones pretty simple:\nhttp://www.nasa.gov/centers/langley/images/content/114284main_EM_Spectrum500.jpg\nor pick one from here:\nhttp://images.google.com.au/images?q=electromagnetic+spectrum&hl=en&btnG=Search+Images
285416
We really only know our solar system planets, and we know from probes that have been sent, from the effects on their moons and other bodies coming close or even hitting into them. We can observe how the spectrum of the atmosphere changes when the planet goes behind or for Mercury and Venus, in fron of, the sun's halo. Or when the planet "occults" another star whose spectrum is known.
117146
It's the same way that scientists look at all massive measures: density*volume.  The density (ie the number of stars per square lightyear) is assessed by counting the frequency of galaxies and the size of galaxies.  The mass of galaxies can be inferred by the speeds of rotaion, and the mass will give you an idea as to how many stars there are in the galaxy by looking at the average mass of a star.  Then you get a sense of how many galaxies are in a given volume of space.  They use this, and extrapolate from the size of space (set by the tenets of general relativity, the Big Bang theory, the red-shift observed speed of expansion, etc), and they can thereby infer how many stars there are in the universe.\n\nIt's like the mass of the earth.  We can't figure it out with 10 kilograms, or even 100 kilograms, but we can get an idea as to the magnitude of the mass.  With magnitude, i mean the number of digits to the left of the decimal place.  We call the difference between 10 and 100 "one order of magnitude," and the difference between 100 and 100,000 "three orders of magnitude."  Such scales are commonly used in science for things where exact numbers are impossible to get, but the range of magnitude is important.  Some such commonly known scales are the measure of sound in decibles, the Richter scale for earthquake power, and the pH scale for acidity.  With a pH of seven, one can infer that a liter of water has 3,344,000,000,000,000,000 hydronium ions per liter, whereas it only has 3,344,000,000,000,000 hydronium ions per liter at a pH of 10.  In these cases, the magnitude, rather than the exact number, is the matter of interest.\n\nIt's the same in counting stars.  We can't know the exact number of stars, especially since they constantly form and die--but we can get a pretty good idea as to the magnitude of the number by looking at stellar density and extrapolating the size of the universe.
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We don't detect amino acids in stars directly, they need a much cooler environment to form and stay together.  We have found them in asteroids and comets within our own solar system, and have observed them in clouds of insterstellar gas.\n\nThe "we are all made of stardust" comment comes from the relization that all of the elements heavier than hydrogen and helium are created in the cores of stars, or in the violent deaths of some stars.  All the elements that make up you, me, this planet, everything were formed inside of stars and then blown out upon the cosmos to be reincorporated into new structures.  Kind of neat actually.
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There are three basic methods:\n\n1. Parallax. The angle at which the object appears in the sky is very precisely measured at one point in the Earth's orbit, then measured again six months later. Since the Earth is in a different position at these times (186 million miles between the two measurments), the star will appear at slightly different angles, and its distance can then be worked out from these angles using simple trigonometry.\n\n2. Standard candles. Certain types of stars (Cepheid variables, RR lyrae variables), and certain types of stellar events (type Ia supernovae), have luminosities that can be worked out fairly precisely from their intrinsic properties (the variable stars for instance, have a period of variablility that is closely correlated with their luminosity, and the type Ia's luminosity can be worked out by examining its light curve). Since percieved luminosity varies inversely with the square of the distance, and since we konw how much light they put out at the source, we can work out how far away these stars are simply by measuring how bright they are.\n\n3. Redshift. The universe is expanding, and that means that from our perspective, distant galaxies are all moving away from us. This means that the light we recieve from them will be at a lower frequency (that is, redder) than the light they emitted, due to the doppler effect. Edwin hubble discovered that at large scales, the observed redshift is directly proportional to the distance of the object from us. This means that if the object is too far away to measure using parallax and lacks a good standard candle, we can still determine its distance simply by measuring its velocity. Actually doing this is somewhat difficult, and involves looking for patterns in the absorption lines in the object's spectrum to figure out what elements created those lines, and then one you know that you can figure out what the frequency of the light should be. After that, you have to work to filter out as many extraneous sources of redshift as possible, such as the object's gravity, its velocity due to gravitational interactions with other nearby objects (what is called the peculiar velocity), and so forth, to leave just the velocity due to the expansion of the universe - from which the distance is estimated using hubble's law.
633777
Maybe this explanation can help? http://en.wikipedia.org/wiki/Spectral_density
308236
When performing star counts, astronomers consider many different categories which have created been to classify a few stars that have been well studied. One of the hopes of studying the results of star counts is to discover new categories. Different counts typically seek to categorize stars for only a few of the qualities listed below, and determine how common each considered quality is and how stars of that kind are distributed.\n\nTemperature. In astronomy, temperature is usually shown using the letter codes O B A F G K M L T running from blue (type O) through white (type F) to red (type M). Types L and T are used for brown dwarfs, whose 'colors' are in the infrared. \nSize. Size is usually designated by Roman numerals I (supergiants) through V (dwarfs). \nAge. Stars are usually grouped into Population I (young) and Population II (old). \nLocation. In the Milky Way Galaxy the groups are described as thin disk, thick disk, central bulge, and halo. \nMultiplicity. Most stars appear to be members of double star or triple star, or even double-double star systems. Our own sun appears to be rare for not having a companion star. \nThere are many finer subdivisions in all of the above categories.\nIn which category you want me to count the Stars.