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1

When you point your 25 cm aperture Newtonian reflector at the Sun you're concentrating sunlight to about 50 watts per square centimeter. About half of that is in IR/UV and will be absorbed in many kinds of optical glass and the rest will be available for imaging, and way too much for it! If you want to use your full aperture, then you must put a special ...


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Arecibo recently opened the Arecibo Observatory Data Archive, which allows folks to obtain data organized by project. About 1800 proposals are listed, although not all of those have data available because not all of the observatory's data has been transferred to its new home at the Texas Advanced Computing Center. There's also an 18 month period during which ...


2

Dark or bright features does not matter - the resolution stays the same. Resolution is achieved when the diffraction pattern is such that two maxima or two minima can be distinguished. Many pictures exist of the ISS in front of the Sun or the Moon, and 10" is definitely a telescope with enough aperture. The question one has to ask is: do you mean to ...


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From http://www.mmto.org/history-of-the-telescope/ After nineteen years of productive operations, progress in the production of large mirrors (pioneered at the University of Arizona’s Mirror Lab), and new instrument technologies drove the desire to upgrade the telescope to utilize a single 6.5-m mirror in place of the smaller six-mirror array. The ...


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If you manage to collimate it then that telescope should show you, under dark skies, a fuzzy light patch which is the core of the galaxy. You won't be able to see the jet with that telescope, that needs a much higher aperture. I'm sorry to tell you this, but the telescope you bought is notorious for being not very good. The powerseeker line has a whole sub-...


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No we can't, The Wikipedia article states that: the size and shape have not been directly observed as ʻOumuamua appears as nothing more than a point source of light even in the most powerful telescopes In addition, note c states that: Brightness peaked at 19.7 mag on 18 October 2017, and faded below 27.5 mag (the limit of Hubble Space Telescope for fast-...


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A lot of the low-end refractors are limited by the cheap eyepieces. I have picked up some of these at garage sales and using high quality eyepieces found them acceptable for entry level use. Anything advertising 900x is showing a theoretical magnification. Atmospheric turbulence and optical quality means that they will be useless at those magnifications....


1

Yes, you can remove the solar filter during totality - otherwise you will have no way to see the corona (or anything at all) through the telescope during totality. The dangerous time is (as you also say yourself) towards the end of totality - and it's easy to get lost in time and the joy of the moment. Set a timer to wake you seconds before end, have others ...


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If your willing to accept more than 2 discontinuous mirrors, the Three Mirror Anastigmat has 4 passes along some/most of the overall tube length. An early working prototype example (which I've actually seen in person many years ago) was built at the University of Cambridge by Dr. Roderick Willstrop. The Institute of Astronomy has a page on the Three Mirror ...


4

Cool question! If you allow for flat mirrors, I've seen five myself. Answer(s) to How did I flip some mirrors around in the dark at 3 AM and change the focal length of a 24 inch Boller and Chivens? show four mirrors and there was one more on the floor below to make the beam horizontal. If you count the aluminized reflective grating as a mirror it was six. ...


1

...is it possible to connect a reflector telescope and a refractor telescopes (like monocular for bird watching) together... Yes, a properly focused telescope (for someone who's not near-sighted) will have infinity conjugate focal points; parallel rays in make parallel rays out. If the telescope is set up for 50x magnification (f=600 mm objective, f=12 mm ...


3

Absurdly cheap and (potentially) very fun! The absolute cheapest telescope to make would be extremely hard to make, you'd be doing something for the first time, but it would at least be fun! Make your objective lens out of ice, and find a way to polish it smooth. Don't make it as big as these though. You can then use an eyepiece out of a pair of old ...


2

I won't discuss the utility of doing this or if there are better ways to make observations with dark skies, but to your question, as asked, Would it be possible to mount a telescope on a high quality drone and fly above the light pollution to get better star shots (if the wind allows it of course)? the answer is Yes, certainly! and don't let folks tell you ...


7

The short answer is that blurring destroys information, and no amount of correction after the fact can bring it back. A slightly less short answer: As others have mentioned, the blur caused by imperfections in the mirror is a convolution of the true image with the "point spread function" created by the imperfections. Convolution of the image is ...


2

To solve this problem, you can replace the telescope imaging system with a simple pinhole (conceptually) and just draw the rays that pass through the center of the entrance aperture. The Moon is about 29 to 34 arc minutes wide or about 0.0085 to 0.01 radians. If your telescope has a focal length of 200 cm, then at the focal plane it will be 1.7 to 2.0 cm ...


5

"Above the light pollution" is really high and the stratosphere is a good starting point, because most of the atmospheric light scattering happens in the troposphere. Quite a few technical and regulatory obstacles here. On the other hand, directional instability (down to motor vibration) and astrophotography don't really play well. You need to ...


0

In situations where one is using a camera to look at a brightly glowing or brightly illuminated object at relatively short range, and one can observe the object for a long time without it changing, the total amount of information present in the incoming photons will be much greater than the amount of useful information one would want in a final image. Using ...


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correct for the distortion An imperfect mirror does not produce a distorted image - it produces a blurry image. With light-field sensors and phase imaging, one could possibly correct for the blur, but it is much more challenging problem than normal lens distortion correction. Distortion refers to a systematic change in how shapes are projected in an image. ...


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Yes, but not in the exact way you think of. To avoid light pollution it is better to go sideways. If you are in a light-polluted city, there would still be light pollution at an altitude of 400ft (the maximum operating altitude of drones) And, moreover, amateur drones are not powerful enough to carry a telescope of any useful size. So you will find that ...


6

They do corrections in computers. But it's not a perfect thing. Just how you can't tell the difference between 1 + 2 + 1 and 1.3 + 1.4 + 1.3, the equations we solve don't have just one solution. They have many. So we have to do guesses in the algorithm. Given that science is exploring that which is just outside of our knowledge, its useful to get actual ...


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Also see answers to Could mirrors be replaced with CCDs? Is Digital Adaptive Optics Possible? The problem is that light imaging detectors convert amplitude to power during the detection process. Phase is lost. If you had maps of both the magnitude of the electric field and its relative phase, and had this at each wavelength of light, you could do exactly ...


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The image which is recorded by CCDs are the convolution of the true image and a point spread function. If the PSF is not a nice function, such as this one, for example [source]: then (I think) it is hard to deconvolve the detected image from the PSF to get the true image. For example, you don't necesserily know the exact PSF if the telescope is only "...


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