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1

The competition for permanent positions in astronomy is very tough. The field as a whole produces roughly ~200 Ph.Ds per year, but there are usually only a handful (say ~10) tenure-track positions that open up every year. So perhaps ~5% of Ph.Ds end up in tenure-track positions in astronomy. There are more permanent positions in astronomy that aren't ...


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A Celestron Nexstar 130 SLT is not suitable for spectroscopy and the only photography that it will be mush use for would be afocal or DSLR imaging of the Moon (or Sun with a suitable filter). For more serious work you will need a equatorial mounted scope with a better focuser. Exactly which one to choose will depend of your budget and what you want to do. ...


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In a telescope (actually, in any optical system), the last optical element creates a circular area called the "exit pupil", this area must line up with the pupil in your eye (the "entrance pupil" for the optic system called your eye). If the two pupils don't line up, you won't see any of the light the telescope gathers.


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This is completely normal behaviour. What you are seeing is the edge of the projection angle for the lense. This is probably sort of what you're seeing? : Typically this is more noticable with cheaper eyepieces as the individual elements are smaller, and have a smaller field of view.


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Most likely would be the the main mirror needs collimating. On big things like the moon you won't notice bad collimation as much as something small like a planet or star.


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To see DSO's you'll definitely have to head out of whatever town you're in by at least 5km, but the further the better. Next, you'll have to have a good knowledge of where to look for them, or a guide. You should be able to see a fair few once you've done that, especially if you've already seen the Orion Nebula.


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Dark Skies are your friend. When Messier was searching for comets, it was before electric lighting and the nights were dark in a way that is rarely seen today. Take a look at the Dark sky map, and try to get somewhere in the blue or black region. Then allow your eyes to become dark adjusted, and to look with the edge or your vision, or learn to do ...


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I'm assuming your question is about fixed dish radio telescopes, like Arecibo. (For what it's worth, there are non-fixed radio telescopes, such as Green Bank Telescope, that target like any other telescope.) Arecibo uses a spherical reflector instead of the traditional parabolic reflector, and a mobile suspended structure above the primary reflector ...


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As Conrad Turner notes, that talk is about a device for blocking the light from another star (one you think might have planets orbiting around it). It's not for blocking the light of the Sun! If you try to look at a planet orbiting around another star, the glare from the star makes it very hard to see the planet. By placing a specially shaped device in ...


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The quantity of light gathered is the important difference. The VLT and its kind can use interferometric methods to achieve the resolution of a much higher telescope - that allows detection of fine detail that previously couldn't be seen. Large single aperture scopes like the E-ELT don't offer such a high resolution, but they collect a larger quantity of ...


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Ok, not sure where you get 200m from, the maximum baseline for the VLT interferometer is 130m. Nevertheless, your question still stands. There are a number of reasons. Firstly, it is important to understand that with relatively limited number of baselines (4 VLTs = 6 baselines) one does not get actual images out of the interferometer, but rather ...



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