Telescope Buying Guide

Nooone asked:


The diameter of the Hubble Space Telescope is 2.4 meters; the diameter of the new Chilean telescope is 9.6 meters.

How many times better is the theoretical resolution of the new Chilean telescope (the best possible resolution that the Chilean telescope could achieve if nothing else outside of the telescope itself acted to make the resolution worse) compared to the theoretical resolution of the Hubble Space Telescope? Again, show your work or explain your reasoning.

masoud asked:


What is the smallest telescope that can be used to resolve the double star y Leo, where the two stars are 4.4″(arcesecounds) apart?

TheOriginalSara asked:


Whatever I see through the finderscope is not what the telescope sees It seems to be some distance off because after searching for a while through the eyepiece I see the object not far off from where the finderscope thought it was, but it takes a very long time and is very inconvenient.
It’s a reflector telescope. If anyone knows how to fix this please explain in simple language thanks!

DNA asked:


I was thinking the Orion SkyQuest XT4.5 Classic Dobsonian, but any other ones that are under $350 would be fine. I want more advice before I buy stuff.
P.S. If there is such thing as a cheap Celestron telescope (’cheap’ as in not over $700), then that would be great!

magiceye2008 asked:


Say the telescope can see at least 400 miles, and the airplane is flying 20,000 feet above the ground at 100 miles northeast of minneapolis. Taking into account the curvature of the earth, can you see the airplane from chicago?

raul asked:


of 8mm, how many photons per second could newton detect with the telescope compared to without? Assume 100% reflectivity of the mirror and that he just used one eye. I squared 33 and 8 and subtracted them from each other. The choices are 8, 17, 33, 38, 1089. I believe it is 1089. Any confirmation?

raul asked:


diameter of 8mm, how many photons per second could newton detect with the telescope compared to without? 8? 17? 33? 38? 1089? I believe it is 1089 i sqaured the diameter of each and subtracted
Assuming 100% reflectivity of the mirror and he used only one eye

manoftrust72 asked:


I’m looking for a telescope where portability matters alot, and I want the clearest astro photograph where all the stars appear very sharp like points, and I would like to find some giant exoplanets. Which telescope is best for astrophotograph and for the money? Cassegrain, Reflector or Refractor?

Phantom asked:


Can you see the surface of a star from using the telescope u buy from the shop?
Just the ordinary one, because I want to buy one.
Like how detailed and how far can you see from using the telescope?
Thank you very much.

john asked:


I got a telescope for Christmas and was wondering if there are any good sites near Perth, where I can the avoid the light pollution to get a good clear view of the sky preferably something easily accessible, as I don’t fancy carrying the telescope to the top of a mountain.