# Tag Info

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It's called gravitational lensing. Here's a link to the wikipedia article on the subject: http://en.wikipedia.org/wiki/Gravitational_lens. Gravity affects everything, including light. A massive object such as a star, a galaxy, or in this case, a cluster of galaxies, bends the path of photons that pass very close to the massive object. Bending light is the ...

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Whether you'll be able to see them depends on the levels of light pollution in your area. As TildalWave mentioned, a number nebulae and galaxies are perfectly observable with the naked eye so unless you live somewhere very bright, you should be fine. Under really dark skies, objects like M31 are very easy to find with the naked eye. Where I live, I hardly ...

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You can see some of them with a naked eye. Many of the Messier objects, including galaxies and nebulae are observable even without any telescopes. As for others, if Charles Messier could catalog them in 1771 with a 4 inch refractor, you should see most using your 3.3 inch reflector too given good observation conditions, knowing where to point and using a ...

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Stereo Vision? Optically, you'll need something like a couple big Fisheye lenses mounted on a helmet. Looking straight through such optics yields horrible distortion, so you'd have to feed the lens' output into CCD/CMOS sensors, and massage that into flattened images your eyes can handle, on a video screen. Perhaps Google Cardboard? Probably doable and light ...

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The angular resolving power of a telescope is approximately $1.22 \lambda/D \times 648000/\pi$, where this is the Airy disc diameter in arcseconds, $\lambda$ is the working wavelength in metres and $D$ the diameter of the telescope primary mirror in metres. For an 8-m telescope working at 500 nm, this gives an angular resolution of 0.05 arcseconds. There is ...

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Ceres varies between mag 9.3 and mag 6.7 which are below the nominal naked eye limiting magnitude of ~5. The gain in limiting magnitude for something like 10x50 binoculars (~4.5 magnitudes) would bring Ceres even at its faintest above the limiting magnitude of about 9.5.

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Making your own telescope is very do-able given basic working skills. Usually a DOB or Newtonian reflector is a good choice. You can buy a mirror and components all ready to assemble or you can choose to grind your own (which is more difficult). If you have an astronomy club in your area check to see if they can help putting your project together. If not, ...

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There is apparently an option on the STSI (Space Telescope Science Institure) website to try their Spike implementation. This doesn't clearly answer your question, as it's not open, and I don't know the language that has been used. However, there is a lot of information in the documents you provided and on the linked website, so maybe you can start your ...

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Go out in the daytime and practice lining up on the leaves of trees on a distant hill or some such. It's easier to find targets when they aren't against a nearly featureless black backdrop. If you have a finder scope, likewise align it to the scope's view using a distant daytime target. At night, look first for the moon to get a feel for how aligning ...

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When the light from two telescopes is combined to make an interferometer, the resolution of the combined instrument is equal to the resolution of a single telescope with a diameter equal the the distance between the two (or more) smaller telescopes. This is the technology you need to view exo-planets to any resolution you want. This has been incredibly ...

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One of us has misread the paper because I think he says he plans to use "Benanaim" which seems to be an alternative name for Alkaid, $\eta$ Ursae Majoris and very much "ultima cauda ursae majoris" and which would, indeed, transit the meridian at around 9pm on that date.

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You're probably asking the wrong question - which I am going to answer anyway, and after that I am going to answer the question you should have asked instead. As a general rule, there isn't much point in pushing the magnification above 2x the diameter of the instrument, measured in mm. 3 inch, that's 75mm, that's 150x max. Beyond that limit, even under ...

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In typical seeing condition you should be able to use a magnification (see here) of about 25-30x per inch of apperture, so for your telescope that is about 100x, in exceptional condition you could push that up to maybe double that. Also the more magnification you use the less contrast you will have in the image, so really you want the lowest magnification ...

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