Telescopes have become a more prominent fixture in curious households. However, many inquiring minds still debate the practicality of the investment depending on where they live.
We all love the stars. We muse over them, gazing at their natural beauty each evening with awe as if it were the first time we saw them.
Witnessing the night sky is a universal experience, but many wish to take that a step further. Personal-use telescopes have grown in popularity over the years. However, some people fear that they are an impractical investment due to the effects of light pollution.
Light pollution is excessive artificial lighting that dims the natural effects of light we get from the stars. A telescope is a helpful, inspiring tool, but the impact of light pollution might pose some challenges for users.
So, realistically, what can you see through a telescope?
Table of Contents
How Big Of A Telescope Do You Need To See Galaxies?
Observing galaxies is a challenging yet gratifying task. The images that you can capture of galaxies are literally otherworldly.
It is possible to see galaxies from some home telescopes, eliminating the need for state-of-the-art laboratories for leisure research and viewing. The biggest challenge with viewing galaxies is the fact that they are rather far from our usual perspective.
Because of this, they are also very faint relative to objects within our solar system like planets. When it comes to viewing things like planets, we benefit from the light provided by the sun.
Sunlight is reflected fairly brightly off the surface of the planets, making them visible to even the naked eye.
Click here to see an example of what Jupiter looks like through a Dobsonian telescope.
When it comes to viewing galaxies, the focus becomes ensuring that your telescope’s specs are a match for your needs.
Aperture and focal length are huge contributing factors to what you can see through your home telescope.
Sometimes, amateur astronomers will start with smaller apertures and focal lengths to really get the gist of what they’re doing.
While this is a good approach, you may find yourself disappointed if your initial goal is to see galaxies. Viewing a galaxy through a 4-inch telescope will not yield the best results. Instead, aim to purchase a telescope with an aperture of 8 inches or more.
Similarly, it’s a good idea to have a focal length of 1200 mm or more if you wish to get stellar (pun intended) views of faraway galaxies.
This is true except for some of our neighboring galaxies, like Andromeda. Andromeda is roughly the size of 5 full moons in the night sky.
Aperture is always king when it comes to visual astronomy. The more light you can collect, the easier it will be to view deep sky objects like galaxies.
Deep Sky Objects For Light Pollution
Many deep-sky objects are visible from cities. Urban astronomers have a unique disadvantage; they often have excellent viewing points (such as high-up apartments), but they are sometimes significantly hindered by the effects of light pollution.
This means that fainter objects may be challenging to see with your telescope. For city astronomers, open clusters and high-surface brightness planetary nebulae are wonderful.
Other clusters and galaxies are visible as well, but they may appear faint and fuzzy. It is recommended that you do research based on the amount of light pollution in your area.
From there, you can determine exactly which deep sky objects will be visible with your telescope. The best resource for this is www.lightpollutionmap.info.
Is Owning A Telescope Worth It?
Telescopes for Visual
This is quite a loaded question. Determining the worthiness of any large recreational investment, such as purchasing a telescope, requires significant amounts of research and personal interest.
If your passion for the stars is there, it is undoubtedly worth it to consider your options. However, if you fail to consider the levels of light pollution in your viewing area, you may ultimately find yourself underwhelmed.
Your expectations must be realistic before you purchase a telescope for personal use. These days, high-quality telescopes are rather accessible. It simply depends on your unique needs, desires, and goals.
Light pollution will only be a significant hindrance if you allow it to be.
The Bortle Zone will enable observers to accurately pinpoint the effects of light pollution in their area. This helpful tool diagnoses the sky’s brightness in specific locations on a nine-level scale.
The darkest skies on Earth will be measured at Class 1, and the brightest cityscapes will present themselves as Class 9. For example, if you live in Los Angeles or New York City, you may be in Class 9.
In this case, you will want to research the surrounding areas via the light pollution map. Determine if you can get to darker skies within a reasonable driving distance and if this is something that you are willing to do.
Telescopes for Astrophotography
While light pollution is a significant consideration for visual astronomy, it’s a bit less of a concern for astrophotography.
There are two ways to overcome light pollution if you live in a city. The first is simply more integration time on broadband targets. When I say broadband targets, I mean objects that can’t be imaged solely with narrowband filters. These objects include galaxies and star clusters.
With enough total integration time (the total time spent imaging when you add up all of your sub-exposures), you can still get great images even under light-polluted skies. Just be aware that when I say a lot of integration time, I do mean a lot.
Some of the best astrophotography images you have seen are likely 20-30 hours or more of total integration time, and those are under reasonably dark skies.
I already sort of gave away the second option above, and that is to use narrowband filters. If you live in a major city with Bortle 9 skies, these are a must-have. Narrowband filters only allow light from a certain bandpass to enter your camera’s sensor, blocking out all other light.
The catch is that they only work on targets that emit Hydrogen, Oxygen, or Sulfur.
You can get other narrowband filters, but the 3 mentioned above are the ones most commonly used. Targets that you can image in narrowband include:
- The Orion Nebula
- The Horsehead Nebula
- The Veil Nebula
- The Heart Nebula
- The Rosette Nebula
- The Elephant Trunk Nebula
- The Wizard Nebula
- The Crescent Nebula
This list is just scratching the surface; there are tons of targets that you can image in narrowband. As you probably noticed, all the items listed are Nebulae and not galaxies.
Conclusion
What you can see with a telescope visually really depends on two factors. You can see the planets just fine from anywhere, but light pollution and your telescope’s aperture are significant factors for deep space objects.
I would consider Bortle 3 and lower to be light pollution levels conducive to a great visual astronomy experience. However, if you live in a Bortle 9 zone, your ability to see faint deep space objects will be seriously hindered.
For Astrophotography, owning a telescope is always worth it, in my opinion. Of course, if you are under heavily light polluted skies, you will want a monochrome camera with narrowband filters.
Using this type of equipment (just like this whole hobby in general) does have a pretty significant learning curve.
Once you are past that, it’s an incredibly rewarding hobby to be involved in.
If I can do it, so can you.