# Tag Info

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Your telescope is not focused (most likely), or is having some major collimation issues (less likely). Try and move the eyepiece back and forth a little. Go through the whole range of the focuser. You must catch the primary focal plane in order for the image to become clear. If that doesn't work, pull the eyepiece out a few mm and try to move through the ...

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You've put in the moon filter, right? The moon is awfully bright without it. In any case, take the scope out in the daytime, and try focusing on distant objects; the tree at the end of the block, or the radio tower on top of the hill at the edge of town. A scope is easier to learn how to use when you can see what you're doing.

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If a mount is polar aligned, it becomes very easy to find objects that have the same Right Ascension or Declination as a bright star. It works like this 1) you align the mount to the pole 2) using a star map, or an app, you try to find an object that has the same R.A. or declination as a bright star. As an example, use Messier 4, which has almost the same ...

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It's just as simple as taking the flux at some wavelength (just a number) and using this number to represent a visible intensity. If you only have one wavelength then you can only get a monochrome picture. However, if you have flux information at more than one wavelength, let's say three, you can use the flux at the longest wavelength to represent red (r), ...

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Sometimes this can be difficult to wrap your head around in Astronomy, as telescopes generally have a fixed aperture and focal distance, and simply use an eyepiece at the end to make a difference. If you, instead, look at a camera you can get the concept quite quickly. DSLR cameras have swappable lenses and many lenses include non-fixed focal distances ...

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Noctilucent clouds are not a problem for space telescopes because their orbits are always more than 85 km. The Hubble Telescope orbits at about 570 km. Noctilucent clouds are a problem for ground-based telescopes (although only at high latitude sites,> 50$^{\circ}$), especially if you are trying to get accurate photometric brightnesses. However, typically ...

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The objective lens of a telescope forms an real image of the night sky, the size of that image is in proportion to the focal length of the objective lens. The reason for this is simple geometry: If two stars are 1 arcminute apart, and the lens is forming an image of them, then the further the image is from the lens, the further apart the images of the two ...

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Your telescope has a 2000 mm focal length, and 200 mm aperture. With the 20 mm eyepiece, you get 100x magnification. With the 10 mm lens, you get 200x. Several things could cause what you describe: Seeing (turbulence) might be bad. It is common in many places that less than great seeing means everything at 200x and over might start looking blurry. But ...

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The Raleigh criterion is the maximum theoretical limit that ignores the architecture, quality, and state of maintenance of optics. It basically says "assuming the optics in this instrument are PERFECT, this is the resolution you could get out of it". It's a calculation that looks only at the diameter and ignores everything else. In other words, no matter how ...

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The resolution of a telescope is the resolution of the image created by the primary mirror at the focal plane. It provides the minimum separation between two equal brightness stars that appear separate in that image. Often, astronomers put a photographic plate or a CCD at the focal plane, create long exposure photos and these can then be examined at ...

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You have correctly identified a niche for photometers. Another point in their favour used to be that they were much more sensitive in the U-band than CCDs, but I think that newer CCDs can almost match or surpass the U-band response of photometers. CCDs take quite a time to readout. The faster you read them out, generally speaking, the higher the readout ...

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To amplify andy256's comment, the problem that solar telescopes face is that heating of the surrounding ground during the day gives rise to turbulence in the air near the ground, making the observing conditions worse (think of the heat shimmer just above the surface of hot pavement or a hot road -- that's turbulence bad enough for your naked eyes to notice). ...

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Optical telescope sites ideally need to be somewhat remote (to avoid light pollution) yet still accessible for construction, engineering, and observing; high in altitude; dry; with exceptional "seeing" (stable atmospheric conditions); and clear weather. Neither Australia nor Russia really have any sites meeting all those criteria: their mountains tend to ...

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Rather than looking for ready-made systems, take a look at projects. Right now, plenty of amateurs are using software defined radio coupled to various antennas for astronomy. Start here: http://www.rtl-sdr.com/rtl-sdr-for-budget-radio-astronomy/ And while it has nothing to do with imaging, there's plenty of radio astronomy that amateurs can do using simple ...

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Russia has BTA-6 which is a 6m optical reflector telescope (which is good enough for their research). Additionally, Australia is a member of many telescope projects throughout the world, and one of them (3.89m telescope) is in Australia itself. Have a look at the link here.

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From my simplistic analysis, it's not good for much. For comparison, the first radio telescope was 9 meters. One of the favorite parts of the spectrum for radio telescopes is the water hole - 21 cm. From my quick mental arithmetic, this dish would be able to resolve sources of 21 cm signals of they were about 5 degrees apart. I'll update with links and ...

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