Characteristics of astronomical telescopes

Telescopes are instruments that have an astronomical function, since they are used to observe the stars. There are many astronomical telescopes, with different shapes, sizes and functions, so many that it is necessary to make a classification of their characteristics, so that we can know which is the one that adapts to our needs.

If you are starting out in the science of astronomy, you should know that the efficiency of a telescope is related to its opening or diameter, which is expressed in millimeters.

Therefore, the first feature to look at is its diameter. But, it is also important that we know the types of astronomical telescopes that exist.

Types of astronomical telescopes

The list is not very long, since basically there are two types of astronomical telescopes, reflectors and refractors. The difference is in the type of component they contain to observe the stars, since they can be lenses or mirrors.

But, depending on which of those components it is, you will need a larger or smaller diameter or opening.

A telescope that uses lenses to observe the stars is a refracting telescope, while a telescope that uses mirrors is a reflecting telescope. Another feature that sets them apart is the way they use light, to give us the kind of stargazing we want.

For that reason, to determine what kind of telescope is most effective for the activity we want to develop, it is necessary to have some knowledge of optics and how light is used.

Most experts recommend using a telescope of the reflector class, which is the one that uses mirrors to capture the light of the stars.

A reflecting telescope should have a diameter between 100 and 200 millimeters, but in a refractor class telescope, which is the one that uses lenses, its assembly and handling can be a little more complicated. In addition, it is recommended that it have, at least, a diameter that ranges between 60 and 90 millimeters.

If you are going to start in this activity, there is some knowledge that you must master, among them, learning to read a map or guide to the night skies, which is a tool that facilitates astronomical observation.

You also need to know about an item called an eyepiece, which is purchased separately from telescopes to improve their functions.

But, among all the knowledge you need, it is important that you know and know how to differentiate the characteristics of astronomical telescopes, so that you understand how to manipulate their parts and make them work perfectly, according to your purposes.

Characteristic elements of the astronomical telescope

These are the three elements or sections that you must learn to recognize and manage, so that you obtain the maximum results from your observations, and they are:

  • Types of optics
  • Types of mount, y
  • Tripod

Types of optics

As we have indicated before, optics are of two kinds, refractive and reflective.


The range of its diameter or opening is very important, because they are made exclusively by lenses, the interesting thing is that they require little maintenance.

They are simple to use, excellent for observing the solar system and usually have a medium or small aperture, although sometimes their tube can be large and uncomfortable to handle.


If it is a reflecting telescope, which is also called Newton, it is made up of curved mirrors, so they have a larger aperture and more power, as well as more observation possibilities

Then you will not only be able to see our Solar System, but the nebulas and galaxies. Its tube is open, so the mirror at the end needs maintenance.

Mount Types

The fact that a telescope has quality optics will not make it work perfectly if it does not have a very stable mount. If the mount is not stable, if it moves, or does not allow us to make movements that are precise, this will be a great obstacle for our observation activity. That is why we must know the types that exist.

The kinds of mounts for astronomical telescopes that exist are divided into three types, which are altazimuth, equatorial and computerized:

The Altazimuth Mount

It is the one that facilitates two kinds of movements, which are up-down and right-left. This type of mount is simpler and cheaper, the most common being the Dobson type, which looks like a box that is placed directly on the ground. But tracking the objects we want to observe has to be done manually.

The equatorial mount

This mount requires to be placed on an axis, which is parallel to the Earth's axis of rotation. This peculiarity will allow tracking of the observed object, compensating for the movement of the rotation of the earth when turning a wheel and there are mounts of this type that have a motor capable of executing this rotation automatically.

The computerized mount

It is the one that has a computerized search system incorporated, integrated by electrical elements, which help to carry out the search for celestial bodies in a simple way. They require the equipment to be oriented before starting the observations, but after that, they will execute everything, including object selection and tracking, automatically.

The Tripod

This is one of the essential elements of an astronomical telescope, because it is what holds the mount and the optical tube or telescope. That is, it is what unites the entire device.

For that reason it has to be strong enough to hold it steady. It can be made of metal or wood, but must be proportional to the equipment it will hold.

There is currently another option, in the case of fixed astronomical telescopes, and that is to use a fixation column. They are usually made of metal, although in astronomical observatories there are also columns that can be drilled for better fixation. So if the telescope is going to remain stationary, placing a column is the best decision.


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