In short, an average telescope and with dark skies and conditions, you will be able to see Galaxies. You can expect to observe more and see different types of galaxies as the quality of your telescope and your experience and ability increases.
Obviously, what you see will depend dramatically on the specification of your telescope. The specification in which you should be most concerned with is the Aperture (the amount of light it can collect) and the Magnification of your telescope. I’ll include a few examples below which outlines some of the galaxies you can expect to see.
As a general rule, the lower the Aperture the less galaxies you will be able to see and with less detail. You can expect to see faint structures of certain galaxies with a 4″ telescope, galaxy features with an 8-10″ and finer details and considerably more galaxies with a 12-16″+ Aperture telescope.
In essence, the more aperture you have, the darker the conditions and the better observer you become, the more galaxies and details you’ll be able to see. It follows that the smaller telescopes show only the brightest galaxies, but if you want to see significant details in them, a larger 10″ or 12″is required.
I’m assuming you googled whether you can see galaxies with a telescope because you’re trying to figure out what telescope you can buy and successfully use to observe the night sky. Always consider what and how much you want to see, in how much detail and structure and the ease of use of the equipment.
In general, a telescope of a 6″ Aperture and above is the minimum Aperture you should consider if you are primarily focused on observing galaxies.
These are a just a few examples of what galaxies you can see at different telescope Apertures:
- 4″/101mm Telescope = The two Magellanic Clouds and M33, M81, M82
- 6″/152mm Telescope = Messiers and NGC’s
- 8″/203mm Telescope = Considerable structure and views of the Magellanic Clouds and M31, M33, M51, M66, M82, M83, M101, NGC 253, NGC 2403, NGC 2903
- 12″/ 304mm Telescope = H-II regions and the star like inner cores of brighter spiral galaxies.
- 16″/406mm Telescope = Large numbers of Spiral Galaxies
Consider that the higher the aperture of the telescope, the more fainter galaxies and the more detail you will be able to see on each galaxy outlined above. So a 16″ can see all of what is possible with the lower ” Aperture models above, but in greater detail and clarity.
Telescope Specification to Observe Galaxies
If you are looking to purchase a telescope for viewing galaxies, there are certain things you should look out for. Below, I run through the different specification and what you will most likely need.
All astronomical telescopes, regardless of their size, are designed to do two things:
(1) Brighten an image
(2) Magnify your views of celestial objects.
Refractors, Reflectors, and compound telescopes will do this this in different ways, but the commonality between them are:
As mentioned previously in this article, the most important specification to consider for your telescope is your Aperture. This is true regardless of whether it is a Refractor, Reflector or Compound Telescope.
The Aperture is word to describe the diameter of the telescopes main, light-gathering lens or mirror. (the lens or mirror is called the telescope’s objective.) The bigger the aperture, the sharper and brighter your views will ultimately be.
This is essentially how far you can “zoom in” on an object. It is referenced as a multiple of what you can see greater than with your naked eye. So 50x magnification is (50 times what you see with your naked eye). The larger the Aperture, the more Magnification you will be able to use with the best results.
It is possible to increase the magnification on any telescope (to do this you would change the eyepieces). However, if the telescope does not have sufficient Aperture, then high magnification will be ineffective (objects will appear blurred).
In terms of application, a telescope with a maximum magnification of 50x (50 times the magnification of your naked eye) before it provides blurry images, will enable you to see minor detail of the brightest star clusters and galaxies.
However, if you are looking to observe finer detail, you would be looking for a telescope that can provide clear views at 150x magnification +.
If your optical quality and observing conditions are good, it is possible to get 20x to 50x of sharp magnification for every inch of aperture. So, a 4″ telescope can give you a max of 200x magnification, whereas a 6″ telescope works optimally at 300x magnification.
This is the maximum, the best views a telescope can provide will be at their lowest power.
One final thing to consider is the Focal Length. Now different telescopes of the same Aperture will have different Focal Lengths. Generally, the higher the Focal Ratio and the longer the telescopes focal length, the better it will be at high magnification.
This will also enable you to use longer-focus eyepieces which are much easier to use.
Telescope Accessories to View Galaxies
With a telescope there are also some extra components which improve and alter its performance. Here are the ones to consider if you are looking at observing galaxies.
Eyepieces are the component that form an image from the light your telescope collects. Eyepieces are essentially small magnifying glasses that help you view an image.
It is possible to change eyepieces on telescopes which will help you manipulate the magnification.
The majority of telescopes will provide a couple of eyepieces in the box, but you can also buy them separately. Its best to get a set that provides you with a range of different magnifications.
There are many different designs, but generally, the more expensive the eyepiece, the greater the quality of the elements it is composed of and ultimately the greater the image it will provide.
Another accessory to consider for your telescope is a finder; this will help you to identify and observe objects in the sky like Galaxies far more easily and effectively.
This is because even at its lowest power, a telescope (and any eyepiece) is going to show you a very small section of the sky. Its therefore impossible to really know where you are aiming.
A finder therefore helps to overcome this issue. There are different types available starting with a basic “peep sight” ranging to “reflex” sights that utilize red dots and circles to help you mark objects in the sky.
The better telescopes will have a finderscope included, but you can also purchase them separately if you wanted to upgrade.
Final Words and Conclusion
Observing galaxies is one of the best and most fascinating observations for an Astronomer.
In summary, if you want to observe galaxies, always consider which ones, in what level of detail, and then think about your budget and preferences. The greater the Aperture of the telescope the more you will ultimately be able to see – but these telescopes typically cost more.
There are other instrumental factors, primarily having the right sky conditions (dark skies) and building on your experience, that will dictate what galaxies you are able to see. Training your eye requires a lot of practice and a commitment to observing on a regular basis.
If you are looking for a new Telescope to purchase to observe both Planets and Galaxies, I suggest you read my comprehensive guide here.
Best of luck!