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| | More About Stars |
 | | To modernize the magnitude system, we define the scale such that a difference of five magnitudes is exactly a factor of 100 in apparent brightness. Also, the scale is extended to magnitudes smaller than 1 and larger than 6. Decimal magnitudes are also permitted. | | | If the star is closer than 10 pc, its apparent brightness increases, so its apparent magnitude becomes a smaller number (since smaller magnitudes mean brighter stars) than its absolute magnitude. | | | Pollox has an apparent magnitude of 1.1 and an absolute magnitude of 1.1. Epsilon Eridani has an apparent magnitude of 3.72 and an absolute magnitude of 6.1. From which of these stars do we receive more light at earth? |
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http://www.physics.rutgers.edu/~abragg/110/lecture7.html
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| | More About Stars |
| | To modernize the magnitude system, we define the scale such that a difference of five magnitudes is exactly a factor of 100 in apparent brightness. Also, the scale is extended to magnitudes smaller than 1 and larger than 6. Decimal magnitudes are also permitted. | | | A star’s absolute magnitude is equal to the apparent magnitude that it would have if located at a distance of 10 pc from the observer. | | | Pollox has an apparent magnitude of 1.1 and an absolute magnitude of 1.1. Epsilon Eridani has an apparent magnitude of 3.72 and an absolute magnitude of 6.1. From which of these stars do we receive more light at earth? |
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http://www.physics.rutgers.edu/~abragg/110/lecture7.html
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| | Pleiades Photometry |
| | After the integrations are completed, the apparent magnitude of the object under study is displayed in the message box. | | | By overlaying and aligning these main sequence stars on top of your apparent magnitude H-R diagram, you will be able to relate the apparent magnitude (m) of a cluster star to an absolute magnitude (M) from the main sequence plot. | | | The color index, B-V, is the apparent blue magnitude (B) minus the apparent visual magnitude (V). |
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http://www.phys-astro.sonoma.edu/courses/a231/pleiades_photometry.html
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| | Apparent magnitude - Wikipedia, the free encyclopedia |
| | In 1856, Pogson formalized the system by defining a typical first magnitude star as a star which is 100 times brighter than a typical sixth magnitude star; thus, a first magnitude star is about 2.512 times brighter than a second magnitude star. | | | The brightest stars were said to be of first magnitude (m = 1), while the faintest were of sixth magnitude (m = 6), the limit of human visual perception (without the aid of a telescope). | | | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. |
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http://www.marylandheights.us/project/wikipedia/index.php/Apparent_magnitude
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| | NSW HSC ONLINE - Physics |
| | Absolute magnitude uses the same scale as apparent magnitude, and is arbitrarily defined to be the same as the apparent magnitude the star would have to an observer at a distance of 10 parsecs from the star. | | | Magnitude is expressed as a number which increases as apparent brightness decreases. | | | The magnitude scale is now arranged such that an increase in magnitude by 1.0 represents a decrease in apparent brightness by a factor of 2.512, and a star of magnitude m is 100 times fainter than a star of magnitude m - 5. |
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http://hsc.csu.edu.au/physics/options/astrophysics/2977/PHYS974net.html
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| | apparent magnitude concept from the Astronomy knowledge base |
| | The brightest star of all, of course, is the Sun, whose apparent magnitude is -26.74, followed by Sirius, whose apparent magnitude is -1.46, Canopus (-0.72), Alpha Centauri (-0.27), Arcturus (-0.04), and Vega (+0.03). | | | abstraction > mathematical concept > number > quantity > radiation measurement > magnitude > apparent magnitude | | | photovisual magnitude (2 facts) - The magnitude of an object as measured photographically by filters and emulsions that are sensitive to the same region of the spectrum as the human eye. |
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http://www.site.uottawa.ca:4321/astronomy/apparentmagnitude.html
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| | ASTRONOMY 102- LECTURE 11 |
| | We assign apparent magnitudes to objects in the sky by comparing their brightness with a standard star of known magnitude: Vega, one of the brightest stars in the sky, for instance, is chosen to have magnitude 0, and other stars can be assigned numbers compared to it. | | | The apparent magnitude, abbreviated m, is just a number that is assigned to designate the brightness of a star (B, the amount of energy we receive). | | | The absolute magnitude of a star is defined as the apparent magnitude the star would have at a distance of 10 parsecs. |
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http://www.gettysburg.edu/academics/physics/CLEA0/A102ol11.html
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| | Stellar Magnitude |
| | Apparent and absolute magnitudes are measured by instruments sensitive to a small wavelength interval of the radiation continuum, such as the visual band: approximately 400 nm/7 | | | Absolute magnitude is the apparent magnitude that a star would have if it were located at a standard distance of 10 parsecs from the Earth. | | | Keywords: stellar birghtness, magnitude, apparent magnitude, absolute magnitude, bolometric magnitude |
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http://www.peripatus.gen.nz/Astronomy/SteMag.html
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| | ASTRONOMY 102- LECTURE 11 |
| | The absolute magnitude of a star is defined as the apparent magnitude the star would have at a distance of 10 parsecs. | | | We assign apparent magnitudes to objects in the sky by comparing their brightness with a standard star of known magnitude: Vega, one of the brightest stars in the sky, for instance, is chosen to have magnitude 0, and other stars can be assigned numbers compared to it. | | | The difference between the apparent and absolute magnitude of a star, m-M, is called its distance modulus, and is readily converted into the distance of the object. |
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http://www.gettysburg.edu/academics/physics/CLEA0/A102ol11.html
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| | apparent_visual_brightness |
| | Modulus: Absolute visual magnitude (Mv) is derived from apparent magnitude (M), the apparent visual brightness of a celestial body without adjusting for distance from Earth, using distance (d) in... | | | The apparent visual brightness of 9.2 magnitudes corresponds to an absolute magnitude of -21.1. | | | Magnitude Summary m v = apparent magnitude apparent visual brightness of a star in the sky M v = absolute magnitude visual... |
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http://apparent_visual_brightness.networklive.org
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| | Curious About Astronomy: What is apparent magnitude? |
| | For some opinions on the pros and cons of the apparent magnitude system (despite its complexity, there are more pros than you might think), have a look at this essay by Steve White from Kitt Peak National Observatory. | | | It is important to point out that apparent magnitude doesn't measure how bright objects actually are; it measures how bright they appear to us, which also depends on how close they are. | | | So the way we find that the Sun has a visual magnitude of -26.74 is that we measure how bright it appears from Earth and observe that we receive around 51 billion times as much light from the Sun as we do from Vega. |
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http://curious.astro.cornell.edu/question.php?number=569
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| | Magnitudes and distance |
| | One method is to determine the distance to the star, measure the apparent magnitude, and scale the apparent magnitude to a distance of 10 pc. | | | Q: Star A has an apparent visual magnitude of 7, and its light intensity is 100 times dimmer than that of star B. What is the apparent visual magnitude of star B? The intensities differ by a factor of 100, which means that the difference in magnitudes must be 5. | | | Table 3: Apparent and absolute magnitudes of common stars |
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http://www.astro.northwestern.edu/labs/m100/mags.html
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| | Apparent magnitude - Encyclopedia.WorldSearch |
| | The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. | | | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. | | | Apparent magnitudes and color indices for seventy-four white dwarfs and degenerate stars |
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http://encyclopedia.worldsearch.com/apparent_magnitude.htm
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| | RR Lyrae Stars and the Distance to M4 |
| | Plot apparent magnitude vs. time (where the time is given in the fraction of the day since the observations started) on a apparent magnitude of star 42 versus time graph. | | | Once you have calculated the diamters of the standard stars, plot apparent magnitude versus diameter (in pixels) on the graph (Apparent Magnitude vs Measured Diameter in Pixels). | | | You will then have a graph of the apparent magnitude of each standard star (y axis) as a function of its measured diameter in pixels (x axis). |
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http://www.astro.washington.edu/labs/clearinghouse/labs/DistM4/m4.html
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| | Example Problems: Apparent Brightness and Luminosity |
| | Well, the star& apparent magnitude is 6, so if it were closer (and therefore brighter), its magnitude would have to be something LESS than 6 (remember, smaller magnitudes mean brighter objects).But how many steps in magnitude would it gain if it were 57.3 times brighter? | | | So if you know the apparent and absolute magnitudes, you just subtract the absolute from the apparent, divide by 5, raise 10 to that power, and multiply by 10.And that’s the distance. | | | DM = apparent magnitude – absolute magnitude = 5 log |
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http://www3.wittenberg.edu/dfleisch/Example2.htm
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| | Example Problems: Apparent Brightness and Luminosity |
| | So if you know the apparent and absolute magnitudes, you just subtract the absolute from the apparent, divide by 5, raise 10 to that power, and multiply by 10.And that’s the distance. | | | Well, the star& apparent magnitude is 6, so if it were closer (and therefore brighter), its magnitude would have to be something LESS than 6 (remember, smaller magnitudes mean brighter objects).But how many steps in magnitude would it gain if it were 57.3 times brighter? | | | DM = apparent magnitude &; absolute magnitude= 5 log |
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http://userpages.wittenberg.edu/dfleisch/Example2.htm
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| | Stellar Magnitude |
| | Absolute magnitude is the apparent magnitude that a star would have if it were located at a standard distance of 10 parsecs from the Earth. | | | The brightness perceived at the surface of the Earth (corrected for atmospheric effects) is known as the apparent magnitude and is given by | | | Keywords: stellar birghtness, magnitude, apparent magnitude, absolute magnitude, bolometric magnitude |
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http://www.peripatus.gen.nz/Astronomy/SteMag.html
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| | Magnitude Scale |
| | The scale for absolute magnitude is the same as that for apparent magnitude, that is a difference of 1 magnitude = 2.512 times difference in brightness. | | | In practice this type of problem is less realistic for actual objects as we can normally measure their apparent magnitudes directly however it may be that we wish to calculate what apparent magnitude a class or type of object may have given the other parameters. | | | If you look closely at the apparent magnitudes for the five named stars in Crux you will see that the brightest star is labelled α, the next β and so on. |
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http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_magnitude.html
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| | Magnitude Scale |
| | The scale for absolute magnitude is the same as that for apparent magnitude, that is a difference of 1 magnitude = 2.512 times difference in brightness. | | | Betelgeuse's apparent magnitude is higher (therefore dimmer) than its absolute magnitude so it would appear even brighter in the night sky if it were only 10 parsecs distant. | | | If you look closely at the apparent magnitudes for the five named stars in Crux you will see that the brightest star is labelled α, the next β and so on. |
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http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_magnitude.html
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| | Wikinfo Apparent magnitude |
| | The brightest stars were said to be of first magnitude (m = +1), those which were only half as bright were of second magnitude, and so on up to sixth magnitude (m = +6), the limit of human visual perception (without a telescope or the like). | | | The absolute magnitude, M, of an object, is the apparent magnitude it would have if it were 10 parsecs away. | | | The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, its brightness without regard to the object's distance from a point of observation. |
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http://www.wikinfo.org/wiki.php?title=Apparent_magnitude
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| | Project Glossary |
| | Apparent magnitude is the magnitude of a star's intensity as measured from the Earth. | | | The absolute magnitude of a star is its apparent magnitude were it ten parsecs from Earth (see `Parsec'). | | | times the intensity of a magnitude of B. There are two measurements of magnitude: See `Absolute magnitude' and `Apparent magnitude'. |
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http://www.rpi.edu/~linc/ProjectGlossary.html
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| | Apparent magnitude - Wikipedia, the free encyclopedia |
| | The second thing to notice is that the scale is logarithmic: the relative brightness of two objects is determined by the difference of their magnitudes. | | | Measures of magnitude need cautious treatment and it is extremely important to measure like with like. | | | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs (~ 32 lightyears) away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. |
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http://en.wikipedia.org/wiki/Apparent_magnitude
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| | Apparent magnitude - Wikipedia, the free encyclopedia |
| | The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. | | | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs(~ 32 lightyears) away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. | | | As the amount of light received actually depends on the thickness of the atmosphere in the line of sight to the object, the apparent magnitudes are normalized to the value it would have outside the atmosphere. |
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http://en.wikipedia.org/wiki/Apparent_magnitude
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| | Apparent magnitude - Wikipedia, the free encyclopedia |
| | The apparent magnitude( m) of a star, planet or other heavenly body is a measure of its apparent brightness ; that is, the amount of light received from the object. | | | As the amount of light received actually depends on the thickness of the atmosphere in the line of sight to the object, the apparent magnitudes are normalized to the value it would have outside the atmosphere. | | | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. |
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http://en.wikipedia.org/wiki/Apparent_magnitude
(1187 words)
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| | Apparent magnitude - Wikipedia, the free encyclopedia |
| | The absolute magnitude, M, of a star or galaxy is the apparent magnitude it would have if it were 10 parsecs(~ 32 lightyears) away; that of a planet (or other solar system body) is the apparent magnitude it would have if it were 1 astronomical unit away from both the Sun and Earth. | | | The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. | | | As the amount of light received actually depends on the thickness of the atmosphere in the line of sight to the object, the apparent magnitudes are normalized to the value it would have outside the atmosphere. |
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http://en.wikipedia.org/wiki/Apparent_magnitude
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| | STELLAR APPARENT MAGNITUDES |
| | A star with an apparent magnitude between 3.5 and 4.5 is called a 4th magnitude star. | | | The apparent brightness of a visible star, called apparent magnitude, is designated by a number usually falling between 0 and 6. | | | The brighter the star, the lower its magnitude number: a first magnitude star is brighter than a second or third magnitude star, etc. Occasionally a magnitude may even be expressed as a negative value, and these are the brightest magnitudes of all. |
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http://homepage.mac.com/kvmagruder/bcp/aster/general/mag.htm
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| | magnitude.html |
| | Absolute magnitude is the apparent magnitude of the astro-body as measured at 10 parsecs (or about 32.62 lyr) (Cl-8): see parsec. | | | Apparent magnitude depends on both the luminosity of the star (energy per unit time in the wavelength band of interest) and distance through the inverse-square law of light. | | | Apparent magnitude is what Ptolemy measured and we see. |
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http://www.physics.unlv.edu/~jeffery/astro/magnitude/magnitude.html
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| | Put the Stars in Order of Distance |
| | The apparent magnitude scale was established in antiquity by the Greek astronomer Hipparchus, who placed the stars visible to the naked eye into six classes with first magnitude being the brightest and sixth magnitude the faintest. | | | The absolute magnitude of a star is defined as the apparent magnitude the star would have if it were at a standard distance of 10 Parsecs. | | | One of the methods astronomers use in determining stellar distances is the relationship between the apparent magnitude of a star and its absolute magnitude. |
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http://collections.ic.gc.ca/universe/distance.html
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| | GAT: apparent magnitude - Wikibooks |
| | Apparent magnitude or apparent visual magnitude is the numerical value of light intensity that we give to stars as they appear (hence the word "apparent") on Earth. | | | Some apparent magnitudes are: -26.8 for the Sun, -13 for the full moon, -1.47 for Sirius, 11.05 for Proxima Centauri. | | | If star a has a magnitude of 1.2 and star b has a magnitude of 5.2, then star a is 40 times brighter than star b. |
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http://en.wikibooks.org/wiki/GAT:_apparent_magnitude
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