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With the right telescope, you’ll see the spiral arms of distant galaxies, the birthplaces of stars, deep sky objects, and even the supermassive black holes at their centers.
Choosing the right telescope size is essential because it directly affects the image’s quality and clarity. A giant telescope will be able to gather extra light and therefore provide more detailed and higher-resolution images. Indeed, your viewing experience is just as good as your telescope size!
In this article, we’ll explore telescope sizes for observing galaxies and how to choose the best one for you.
Can I see galaxies with a telescope?
You can see galaxies with a telescope. Telescopes are powerful tools for observing distant celestial objects, including galaxies. However, the visibility and detail of galaxies will depend on several factors, including the telescope’s aperture, magnification, and light pollution in your observing location.
Galaxies appear as faint, extended patches of light in the night sky. Some of the brighter and more well-known galaxies, such as the Andromeda Galaxy (M31) and the Whirlpool Galaxy (M51), can be observed with smaller telescopes, especially if you are in a dark, light-pollution-free area.
To see galaxies in greater detail and observe a wider variety of them, larger telescopes with greater aperture sizes are often preferred. These telescopes can reveal more structure and details within galaxies, making them an excellent choice for deep-sky observations.
Keep in mind that patience and dark skies are key when observing galaxies, as their faint light can be easily washed out by light pollution. Additionally, using appropriate filters and higher magnifications can enhance your ability to see galaxies and their features.
What types of telescopes are used to observe galaxies?
Observing galaxies requires telescopes that can capture the faint light from these distant objects. Various types of telescopes are used for this purpose, each offering unique advantages:
Refractor telescopes to see galaxies
The refractor telescope uses lenses to gather and focus light. The size of a refractor telescope is determined by the diameter of its objective lens, which is measured in millimeters.
A 60mm refractor is a small telescope well suited for observing the Moon and bright planets. It’s a good option for beginners who want to start exploring the night sky. However, due to its small aperture, it cannot gather enough light for faint, deep space objects such as galaxies and nebulas.
On the other hand, an 80mm refractor telescope is slightly larger than a 60mm telescope. It also offers extra light-gathering power. This makes it suitable for observing a wider variety of sky objects as well as bright details of planets. It’s a good option for intermediate amateur astronomers.
A 100mm refractor telescope is larger than an 80mm telescope and offers even greater light-gathering power.
A great refractor telescope that allows you to observe faint sky objects, such as distant galaxies and nebulas, is the Orion Observer 90mm Equatorial Refractor Telescope. It’s considered a medium-sized telescope that’s ideal for advanced novice astronomers.
Reflector telescopes to see galaxies
The reflector telescopes use mirrors to gather and focus light and are best known for their ability to provide sharp and bright images at a relatively low cost.
The size of a reflector telescope is determined by the diameter of its primary mirror, measured in inches.
A 6-inch reflector telescope (or 150 mm telescope) is a relatively small telescope well suited for observing the Moon, planets, and objects such as star clusters, nebulas, and galaxies. It’s a good option for beginners who want to start exploring the night sky.
An 8-inch reflector telescope, also known as a 200 mm telescope, is slightly larger than a 6-inch telescope and offers a broader view and light-gathering power. This makes it suitable for observing a wider variety of unfathomable sky objects as well as bright details of planets.
The 10-inch reflector telescope (254 mm telescope) is larger than an 8-inch telescope and offers greater light-gathering power.
A reflector telescope is well suited for observing faint deep-sky objects, such as distant galaxies and nebulas. It’s considered a medium-sized telescope ideal for intermediate and advanced novice astronomers.
Reflector telescopes with an aperture larger or smaller than these are also available and suitable for different kinds of observations and levels of experience.
Based on your preference and experience, there are diverse reflector telescopes, but we highly recommend the Celestron-AstroMaster 130EQ Newtonian Telescope! This telescope is ideal for beginners and is very easy and quick to set up.
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Catadioptric telescopes to see galaxies
Catadioptric telescopes are a type of telescope that uses both lenses and mirrors to form an image. They are known for their compact design, making them portable and easy to use. Examples of catadioptric telescopes include the Celestron Schmidt-Cassegrain and Maksutov-Cassegrain.
The Celestron Advanced VX 11″ Schmidt-Cassegrain Telescope uses a combination of a spherical primary mirror and a correcting lens (Schmidt corrector plate) at the front of the telescope. This design allows for a compact and portable telescope with a long focal length and wide field of view.
SCTs are popular among amateur and professional astronomers for their versatility and are often used for observing deep-sky objects, as well as for astrophotography and lunar and planetary observations.
The Maksutov-Cassegrain telescope (MCT) is similar to the SCT but uses a thicker corrector plate that is more strongly curved.
The MCT has a more compact design than the SCT and is known for its outstanding optics, which provide sharp images with slight chromatic aberration. It’s also highly suitable for planetary and lunar observation, as well as for deep-sky objects.
Both types of catadioptric telescopes have a closed-tube design, which makes them more durable and allows for less maintenance than an open-tube telescope.
Do I need a big telescope to see the galaxies?
When it comes to stargazing and observing the galaxies and other deep-space objects, size does not matter. But a big telescope can surely provide you with an incredible viewing experience. So, you don’t need a big telescope to see galaxies or your target object. You just need a telescope with huge aperture size and high magnification power.
A great aperture size allows more light to be gathered, resulting in brighter and clearer images. Also, a telescope with a high magnification power can help to reveal details in distant galaxies.
While a big telescope with high optical quality can undoubtedly provide an incredible viewing experience, it’s not the only option.
Many smaller telescopes, especially those with larger aperture sizes, can be just as effective at observing deep-space objects.
A telescope with an aperture size of 6-8 inches can show you some of the most iconic and brightest galaxies, like the Andromeda galaxy and the Whirlpool galaxy.
Another important factor is the location. The less light pollution, the better. You want to be in a place where the sky is as dark as possible to see galaxies, including the Milky Way. This will increase your chances of tracking objects and seeing galaxies and other celestial objects.
The most important thing is to find a telescope that is comfortable for you to use and that you can easily transport and set up.
With the right telescope and location, you can discover the beauty of the galaxies and have a fantastic deep-sky viewing experience.
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How telescope size affects viewing galaxies?
You can explore the vast universe and discover the beauty and diversity of galaxies through the lens of a telescope.
From the grand spiral arms of the Milky Way to the subtle features of dwarf galaxies, every galaxy has its unique characteristics and visibility through different telescope sizes.
Let’s see how the size of a telescope can unlock a whole new world of discovery.
Spiral galaxies
A spiral galaxy is characterized by its spiral-shaped structure, consisting of a central bulge and spiral arms of stars, gas, and dust that rotate around the central bulge.
The central bulge contains mostly older, redder stars, while the spiral arms contain a mix of young, blue stars and interstellar gas and dust. The arms are also where active star formation takes place.
Spiral galaxies are some of the most common types of galaxies in the universe and are found in many different shapes and sizes.
The Milky Way, the galaxy in which we live, is a barred spiral galaxy, a variation of a spiral galaxy with an additional central bar structure.
The telescope’s size is a key factor in determining the level of detail and the number of spiral galaxies that can be observed.
Larger telescopes with an aperture of 8 inches or more offer greater detail and allow the observation of more distant objects, including spiral galaxies.
To view spiral galaxies, we recommend the Orion 8945 SkyQuest XT8 Classic Dobsonian Telescope. This is a great large-aperture Classic Dobsonian suited for beginner astronomy enthusiasts. It is also available at a very affordable price.
Elliptical Galaxies
Elliptical galaxies are characterized by their smooth, round, or elongated shape and a lack of spiral arms or any other distinct structure.
They are composed of older red stars and lack the bright spiral arms and dust lanes of spiral galaxies.
Elliptical galaxies are found in a wide range of sizes, from small dwarf ellipticals to giant ellipticals that can be several times larger than the Milky Way.
They are also known to have a large central concentration of stars. This is called a central bulge, and a halo of stars surrounds the central bulge.
These galaxies also have a large amount of dark matter, which makes up most of the galaxy’s mass.
Elliptical galaxies are less active than spiral galaxies and are not known to have ongoing star formation.
However, they can still host active galactic nuclei (AGNs) or quasars, extremely bright objects that emit large amounts of energy from their centers.
To perfectly view elliptical galaxies, we recommend the Gskyer Telescope. The telescope comes with a 90-degree star diagonal for comfortable viewing, a 20mm eyepiece, and a 10mm eyepiece, which gives magnification options of 45x and 90x, respectively. It also has a finderscope to help locate objects more easily.
Dwarf galaxies
A dwarf galaxy is smaller in size and lower in luminosity than other galaxies. They typically have a total mass of about a billion times the sun’s mass or less.
They can be found in various shapes, such as irregular, spheroidal, and even dwarf elliptical shapes.
Dwarf galaxies are made up mostly of old stars and contain very little interstellar gas and dust, which means they have very low levels of star formation.
They also tend to have a lower metal content than more giant galaxies, which means they formed earlier in the universe.
Dwarf galaxies are found in a wide variety of environments, including in isolation, within larger galaxies, and in galaxy clusters.
They are also thought to be the most numerous type of galaxy in the universe, making up most of the galaxy population.
For a good view of dwarf galaxies, we recommend the Orion Observer 90mm Equatorial Refractor Telescope. It is great for viewing various celestial objects, including the Moon, planets, and bright deep-sky objects.
Distant, high-redshift galaxies
Distant, high-redshift galaxies are located far away from us in the universe. They have a high redshift, which measures how much the wavelength of their light has been shifted towards the red end of the spectrum.
This redshift is caused by the universe’s expansion, which causes the light from these galaxies to be shifted to longer wavelengths, making them appear redder. The farther away a galaxy is, the greater its redshift will be.
High-redshift galaxies are some of the earliest and most distant galaxies ever observed.
They formed when the universe was still very young, less than a billion years old, and provide us with a glimpse into the early stages of galaxy formation and evolution.
These galaxies are also thought to be the progenitors of the present-day massive galaxies.
For viewing distant galaxies, our best recommendation for you is the Solomark 114AZ 500MM Reflecting Telescope. This telescope has a focal length of 500mm and comes with a 25mm and 10mm eyepiece, giving magnification options of 20x and 50x, respectively.
How aperture size affects the ability to see details in galaxies?
The telescope’s aperture refers to the diameter of the lens or mirror used to collect light.
A larger aperture allows a telescope to collect more light, making it possible to see fainter and distant objects, including galaxies.
The aperture size also affects the telescope’s maximum magnification and ability to resolve fine details and identify star clusters in the galaxies.
Some telescopes with large apertures include James Webb Space Telescope, Gran Telescopio Canarias, and Hobby–Eberly Telescope.
Focal length
Focal length is a crucial factor to consider when choosing a telescope. It determines the magnification and field of view of the telescope.
A telescope with short focal lengths will have a wider field of view and lower magnification, while that with long focal lengths will have a narrower field of view and higher magnification.
Additionally, the focal length of a telescope also determines the size of the image produced and the size of the eyepiece required. This is important to consider when deciding what type of telescope best suits your needs.
Visibility of faint objects
The telescope’s aperture size is crucial in determining the visibility of faint objects within galaxies.
A larger aperture allows a telescope to have high-quality optics and collect more excellent light, making it possible to see fainter objects.
This is because the aperture size limits the amount of light the telescope can collect.
The larger the aperture, the greater the light that can be gathered and the fainter the objects that can be seen.
The ability to resolve details in the galaxy
The telescope’s resolution is determined by its angular resolution. The angular resolution is the smallest angle between two objects that the telescope can distinguish.
A larger aperture allows for a finer angular resolution. This means the telescope can see the smaller celestial object within the galaxy.
For example, a high-quality telescope can resolve individual stars in a galaxy. It can also reveal fine structures such as spiral arms and dust lanes.
This is especially important for studying the properties of a galaxy’s central bulge, where a supermassive black hole may reside—also studying the properties of the spiral arms, where active star formation occurs.
Observing faint objects
A larger aperture telescope can detect faint features such as globular clusters, faint spiral arms, or faint companion galaxies in a galaxy.
A larger aperture also allows for a higher-resolution image, which means that more details of the galaxy can be seen.
On the other hand, a smaller aperture telescope will have a more challenging time detecting obscure objects within a galaxy. It will only show the galaxy’s brighter and more distinct features, not faint ones.
The ability to distinguish between close objects in the sky
The aperture size of a telescope determines the amount of light that can enter the instrument, affecting the telescope’s ability to resolve fine details in an image.
A larger aperture will allow increased light to enter, making it possible to see finer details in an object, including distinguishing between close objects. This is known as the telescope’s resolution.
The ability to image deep sky objects
Aperture size is one of the essential factors in determining a telescope’s ability to image deep sky objects such as galaxies and nebulae.
A larger aperture allows increased light to enter the telescope, enabling it to detect fainter objects and star clusters.
Larger apertures can also provide better image resolution and less distortion, allowing more accurate images of deep-sky objects.
However, the aperture size is not the only factor determining the telescope’s ability to image deep sky objects.
Other factors, such as the quality of the optics, the mount and tracking of the telescope, the quality of the eyepiece, and the observer’s skill, also play a role in the final image quality.
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What is the best telescope to observe galaxies?
The best telescope for planetary viewing would be a large-aperture reflector telescope. Dobsonian telescopes are a good match.
This type of telescope uses a mirror to gather and focus light; the larger the mirror, the greater the light the telescope can gather.
The Orion SkyLine 6 Dobsonian Telescope is a perfect telescope for astronomers to view galaxies. This telescope is mounted on a Dobsonian mount, a simple and stable alt-azimuth mount that allows the telescope to move up and down and side to side.
It is also relatively inexpensive and easy to use. The telescope has a focal length of 1200mm, and it comes with a 25mm Plossl eyepiece and a 10mm Plossl eyepiece, which give magnification options of 48x and 120x, respectively.
It’s worth noting that the best telescope for viewing the galaxies and night sky is an Orion SkyLine 6″ Dobsonian Telescope, which we recommend for you.
How to choose the right telescope size to observe galaxies
Choosing the right telescope size for examining galaxies is crucial as it directly affects the telescope’s ability to gather light and resolve details of the faint deep sky objects.
A larger aperture allows more excellent light to enter the telescope, which enables it to detect fainter objects, such as galaxies.
However, aperture size or focal length are not the only factors to consider when choosing a telescope.
Quality of the optics, mount and tracking system, and budget, as well as your skill level, should also be taken into account.
Identify the type of objects you want to observe
When choosing the right telescope size for observing galaxies, it is important first to identify the type of objects you want to observe.
They could be galaxies, star clusters, nebulae, etc. Knowing exactly what you want will guide you to make the right decision.
Determine the level of detail you want to see in these objects
When deciding on the telescope size, it is important to identify the level of detail you want to see.
A larger telescope with a bigger aperture and focal length gathers greater light, allowing you to see finer details in the galaxy, such as individual stars and structures within the galaxy.
The focal length of the telescope also plays a role in determining the level of detail that can be seen.
A telescope with a longer focal length will provide a higher magnification, allowing you to see more details in the galaxy.
A shorter focal length will provide a lower magnification, giving a broader view of the galaxy.
It is important to consider the balance between aperture size and focal length to achieve the level of detail you want to see in your observations.
Consider your budget and the cost of different telescope sizes
When choosing the right telescope, budget is also an important factor. Larger telescopes with bigger apertures tend to be more expensive.
That’s why it’s important to set a budget and find a telescope that meets your observing needs and fits within your budget.
It’s also important to remember that accessories such as eyepieces and filters can add to the overall cost.
By setting a budget, you can narrow down your options and make an informed decision that balances cost with functionality.
Different telescope sizes and their capabilities for observing galaxies
Apertures of 4 inches and smaller
Apertures of 4 inches and smaller can observe bright and nearby galaxies but may not be able to gather enough light to see faint and distant galaxies in great detail.
These smaller apertures can also not resolve as much detail within the galaxy, and the view may appear more diffuse.
Depending on the focal length and other factors, they may also be less suitable for deep sky observations and more suitable for planetary observations.
However, they are more portable, easy to handle, and have lower costs, which makes them more accessible to amateur astronomers.
We recommend the Celestron – PowerSeeker 127EQ and Orion StarBlast II 4.5 EQ Reflector Telescope Kit telescopes for this category.
Read also: Celestron PowerSeeker 127EQ Review (Before Purchasing)
Apertures of 6-8 inches
Apertures of 6-8 inches can observe a wider range of galaxies, including bright and faint ones.
They can gather greater light than smaller apertures, allowing you to see more details in the galaxy, such as individual stars and structures within the galaxy.
Telescopes with this size can also resolve more detail within the galaxy, and the view will appear more defined.
These telescopes are also suitable for deep-sky observations with the right accessories.
They are also more powerful than smaller apertures and provide a better balance between portability, cost, and functionality.
A good and recommended telescope with six to eight inches aperture is the Gskyer 90mm Astronomical Refractor Telescope; this telescope has high-quality optics and magnification. It is also very easy to operate.
Apertures of 10 inches and larger
Apertures of 10 inches and larger can observe a wide range of galaxies, including bright and faint ones, with a high level of detail.
They can gather a large amount of light, allowing you to see very faint and distant galaxies and resolve fine details within the galaxy.
These larger apertures also provide high optical performance, allowing you to see more of the galaxy in one glance.
However, they tend to be more expensive and less portable than smaller apertures. They require a more stable mount and a larger setup area.
This size is more suited for dedicated or advanced astronomers or astronomical observatories.
A good recommendation for this category is the Sky-Watcher Classic 250 Dobsonian 10-inch Aperture Telescope. This telescope has a sturdy and lightweight design and comes with all the needed accessories.
What is the best telescope for observing nebulae?
A Dobsonian telescope, or a reflector telescope with a large aperture and a wide field of view eyepiece, can be a good choice for observing nebulae.
Also, telescopes with a built-in corrector plate, such as a Celestron Advanced VX 11″ Schmidt-Cassegrain Telescope or an Omegon Ritchey-Chretien Pro RC 154/1370 OTA, are some great options.
This is due to their ability to reduce the distortion at the edge of the field of view.
Best galaxies to see with a telescope
Many galaxies can be observed with a telescope, but some are more easily visible and offer better views than others. Here are a few of the best galaxies to see with a telescope:
The Andromeda Galaxy (M31)
This is one of the brightest and closest galaxies to our Milky Way and is visible to the naked eye on clear, dark nights.
It is a large spiral galaxy and can be observed in various sizes, from small telescopes with 4 inches aperture to larger ones of 10 inches or more.
The Triangulum Galaxy (M33)
This is a spiral galaxy located in the constellation Triangulum. It is a large galaxy and can be observed with telescopes of various sizes.
It has a bright central core and well-defined spiral arms that can be seen with a larger aperture telescope.
The Whirlpool Galaxy (M51)
This is a beautiful spiral galaxy located in the constellation Canes Venatici.
It is known for its well-defined spiral arms and bright central core, making it a popular target for amateur and professional astronomers.
The Sombrero Galaxy (M104)
This is a spiral galaxy located in the constellation Virgo. It is known for its wide, bright central bulge and dark dust lane, which give it the appearance of a sombrero.
The Cigar Galaxy (M82)
This is an irregular galaxy located in the constellation Ursa Major. It is known for its bright central core and elongated shape, which give it the appearance of a cigar.
The Virgo Cluster
The Virgo Cluster is a group of galaxies located in the constellation Virgo.
It is one of the closest galaxy clusters to our Milky Way and is home to over 2,000 galaxies. It is the largest and most massive galaxy cluster in the Local Supercluster, including our galaxy, the Milky Way.
What is the most accessible galaxy to see with a telescope?
The Andromeda Galaxy (M31) is the easiest galaxy to see with an excellent telescope. It is located in the constellation Andromeda and is one of the closest and brightest galaxies to our Milky Way.
This galaxy is visible to the naked eye on clear, dark nights and can be easily located by following the line formed by the three stars that make up the constellation’s “belt.”
The Andromeda Galaxy is a large spiral galaxy and can be observed in various sizes, from small telescopes with 4 inches aperture to larger ones of 10 inches or more.
With the right equipment and clear skies, observing the spiral arms and individual stars is possible. It is also a popular subject for astrophotography and is often captured in detailed images by amateur and professional photographers.
Read also: How Good of a Telescope Do I Need to See Andromeda?
Takeaway—How telescopes reveal the beauty of the night sky
As an astronomer, choosing the right telescope size is one thing you must get right.
You should make choices that align with your aim, budget, and astronomy skills.
Ensure you know more about aperture sizes, focal length, and other key factors before choosing a telescope.
A larger aperture telescope gathers extra light, allowing you to see faint and distant galaxies in greater detail. A smaller aperture telescope may be better suited for observing nearby bright galaxies and celestial bodies.
The telescope’s focal length also plays a role in determining the level of detail that can be seen. A telescope with a longer focal length will provide a higher magnification. This allows you to see more details in the galaxy. But a shorter focal length will provide a lower magnification, giving a broader view of the galaxy and solar system.
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