I am interested in buying a telescope and I would like to use it to look at like galaxies and nebulas.

Right now I'm looking at a 130 mm fast (f/5) Newtonian that comes with two eyepieces of 10 and 20 mm focal length. It comes with a tripod and German equatorial mount that includes fine motion controls for both axes.

This seems about right for what I'd like to do. It's going to be my first telescope and first time to try to look at galaxies and nebulas.

What are other considerations I should weigh before choosing the final one to purchase? Which features might be most helpful for a beginning observer looking for faint objects?

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    $\begingroup$ You have selected that telescope, so why are you asking for suggestions? This seems like a spam seed type of post. Piece of advice, asking for "best" is rarely answerable, however there are comparison sites which will give you the features of a range of scopes for you to make a decision from. $\endgroup$ – Rory Alsop Dec 30 '19 at 19:10
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    $\begingroup$ Hi @Yajanvyas, I think your question might be closed, so I've adjusted it to remove the parts that don't fit the way a good Stack Exchange question should be asked. Now, instead of a "what do you think?" question, it can be answered mostly factually instead of with opinions. Feel free to edit further. And if it is closed (it might still be a duplicate and be answered already) it's not the end of the world, and you can always ask more question. Thanks, and welcome to Stack Exchange! $\endgroup$ – uhoh Dec 30 '19 at 21:23

"Galaxies and nebula" are faint and spread out, and for that very little matters as much as aperture! Back before light pollution was a a serious problem, 6 inches (150 mm) was generally acceptable, these days I tend to recommend 8" or 10" (200 or 250 mm) to just to get through the sky glow.

The 5" scope you are thinking about will be very nice on the Moon, and Saturn/Jupiter and some larger smudges should be detectable but... the view you'll see of "Galaxies and nebula" is not likely to knock your socks off.

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    $\begingroup$ This is an interesting point. +1 Skyglow and "Galaxies and nebula" are both extended objects, and both will increase in brightness by the same factor when increasing aperture area. Aperture buys limiting magnitude for compact objects like stars, but how can it make a nebula increase its brightness relative to sky brightness? I'm probably missing something here. $\endgroup$ – uhoh Dec 31 '19 at 1:46
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    $\begingroup$ I will suggest being able to (usefully) increase power will decrease visible background leading to increase apparent contrast of target object. Think of it as optimal framing. But you are right to be curious, nothing will save the faint fuzzies with a photon count that approaches what sky glow produces. $\endgroup$ – tomc Dec 31 '19 at 23:08
  • $\begingroup$ Well okay if it's brighter it will be easier to recognize a small brightness difference, but the ratio doesn't change. If background is say 20 mag/arcsec^2 and an extended object is 20.5 mag/arcsec^2 then the object will always appear 58% brighter than the surrounding background in any telescope (since the brightnesses are additive in this case). But definitely it will "look better" if it is brighter, up to some sock-knocking-off limit $\endgroup$ – uhoh Dec 31 '19 at 23:27

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