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52

I've made this into an answer because it's too long for a comment, and I really want to show the pictures. It is tempting to think of visible light as "close enough" to (near by wavelengths) and to conclude that "yes, actually, the yellow does affect it. I want a mirror without an obvious tint" However you are wrong, Physics will slap you down. Exhibit A ...


46

If you look at the reflectivity of gold (vs silver or aluminum) you can see a plateau at wavelengths below 500 nm source: If blue wavelengths are not reflected as well as other colors, the resulting image will look "more yellow" - which is what you see. At longer wavelengths, gold is a very good reflector (better than the other two above 600 nm). It also ...


24

Sort of. As Space.com writes, The raw Hubble images, as beamed down from the telescope itself, are black and white. But each image is captured using three different filters: red, green and blue. The Hubble imaging team combines those three images into one, in a Technicolor process pioneered in the 1930s. (The same process occurs in digital SLRs, except ...


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The classic color mapping for Hubble is described in Flase-color astrophotography explained. What you have is (in the Hubble palette): Line Freq True False Ha (656.3 nm) Red -- Green S-II (672.4 nm) Red -- Red O-III (500.7 nm) Green -- Blue An example of this for true color from John Nassr at Stardust Observatory at Coming to Life ...


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I find myself now answering my own question but only because the comment feature is not suited to this "comment". I have selected the answer by @HDE 226868 as my answer and primarily due to the linked Space.com reference. Very good answer to my question. In particular, I also thought this quote from the same page as being important as these reasons (below ...


4

Both From Wikipedia Luminance Versus Luminosity In astronomy, luminosity is the total amount of energy emitted by a star, galaxy, or other astronomical object per unit time. It is related to the brightness, which is the luminosity of an object in a given spectral region. Now your question: Let's assume we have two stars that have the same surface ...


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The current data release is DR12. As to how to interact with the data, it depends somewhat on what you want to do. If you have small queries, for instance if you want data for only a handful of objects, there are a couple of web interfaces. If you have larger queries in mind, CASJobs is a good place to start. You'll inevitably need the schema browser to know ...


2

There is a lot more to it than just astronomy. For example, the tide times inside Boston Harbor are significantly different from those on the southeast coast of Cape Cod. It is true that the primary force behind tides is the position of the Moon, but the macro tidal bulges take a long time to propagate around/across oceans, and then the shoreline shape ...


2

Simply put, it is: how many aliens could we meet? More specifically: The Drake Equation is a way of predicting how many intelligent species there might be in the universe and the likelihood of them contacting us. There are a lot of things that can change the number of aliens we can expect to find. So we use what we know about the universe so far and ...


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You will see Earth, Venus, JupiTer, Saturn. TheY are either bright enough, or come closer to Mars than Earth, that there are no complications/calculations necessary. Uranus is just a naked eye object from Earth (magnitude 5.3-5.9). Its closest approach to Earth, when it is brightest is 17.2 au distant. Mars' orbit takes it closer by about 0.5 au, so you ...


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The instrument should be pointing at an empty ( no stars no galaxies) region of the sky and be able to record very low frequencies Other radiation comes in much higher frequencies from stars , and would not overlap with the low frequency part. >Discovered accidentally in 1964 by Penzias and Wilson (Nobel Prize, 1978), the CMB is a remnant of the hot, ...


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Under the conditions stipulated, the question is a false statement. We would, in fact, be able to "see" the light beam between points A & B. As the photons travel from point A to B, some photons will be deflected (by colliding with the dust particles) in our direction, allowing us to "see" the beam. Only in the absence of dust particles (or any other ...


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Even if your ship traveled at (almost) the speed of light, you would have to follow the trajectory of a ray of light traveling from your point of origin to the star; not from the star to your point of origin. As described, you keep following the trajectories of many different rays of light (emitted at different times) backwards, putting yourself on a curved ...


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Due to the force of gravity, which goes as the inverse of the square, planets trace out an ellipse in space as they orbit around the sun, which is located at a single focus. The other focus is unphysical. Actually, given two massive bodies, their "difference" vector will trace out an ellipse with the center of mass at the focus. Because the sun is so much ...


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You can check The Best Cheap Budget Telescopes Under $200; this presents the latest list of all affordable telescopes that are competent for beginners. Also you can check The cheap telescopes of 2014. Remember always that though magnification is good, but you must need to have a good apparture in your device & for that I prefer Newtonian telescopes or in ...



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