How To Connect Telescope To Computer

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The easiest way to connect and control your telescope with a computer is to use free planetarium software called Stellarium. This software supports many computerized mounts, and after a successful connection, you can control the telescope from your computer.

There are two types of connecting your telescope to a computer. The first one is to connect telescope mount via USB that will allow you to point the telescope on anything you want with the software.

The second type of connection is to place a camera into the eyepiece and connect it with the computer. This connection will allow you to transfer the live image on to your screen, but you won’t be able to control the telescope.

If you combine these two methods, you will get full control of the telescope with the computer. So you can control it remotely and also see everything on the computer screen. This is commonly used in astrophotography and video astronomy. I have already explained how to connect a simple webcam to a telescope to do some basic astrophotography and live viewing here.

This article is focused only on controlling your mount with the computer.

What Do You Need?

You will need a computer, preferably a laptop computer so that you can take it outside with the telescope. You don’t need a powerful system to do this, but I prefer a faster laptop for smooth work. If you use a very old laptop, the whole process can be slow and frustrating and discouraging, and we don’t want that.

Next, you need to download a free software Stellarium. It is very easy to use and well made. It shows a realistic real-time sky in 3D, just like what you see with the naked eye, binoculars or a telescope. This program is available for Windows, Mac OS X, and Linux.

And the last thing we need is, of course, a telescope. But not ordinary telescope. We need a telescope on a computerized mount with some type of GoTo system. I recommend two GoTo telescopes. Celestron NexStar 130 SLT and SkyWatcher 130P so you can check my reviews. The mount will have a hand controller which you have to connect with your computer. Now you can encounter few issues.

Cable To Connect a Computer With a Telescope

This can be a problematic part because cables to connect the computer with the hand controller are usually not provided in the telescope package when you buy it. You have to buy it separately. And you can find two types of connections.

Celestron 93920 NexStar RS 232 PC Interface Cable

The older models of hand controllers only have RS-232 port (landline type connector). In my experience, if you have this type of port on your hand controller, you will get the cable in the package with the telescope. But the problem is that the cable provided is not USB, it is RS-232 to serial port cable. I don’t understand why are some telescopes shipped whit this type of controller and cable. It is 90’s technology, and I bet that there is no computer with serial port in your house anymore.

UGREEN USB 2.0 to RS232 DB9 Serial Cable Male A Converter Adapter 

So, the solution is to buy a Serial to USB reduction cable(link to Amazon). They are easy to find, and they cost a few bucks. With this setup, you will be able to connect your hand controller with the computer via USB. But in my personal experience, it doesn’t work every time because some serial to USB cables are not compatible and they don’t operate.

My suggestion, in this case, is to upgrade your hand controller with a new one. New versions are easy to connect with the computer because you will need a simple USB AB cable. You may be familiar with this type of connection because it is widely used on printers. So you maybe have a few these cables laying around in your house.

USB 2.0 Printer Type Cable – A-Male to B-Male

Still, it took too long when telescope manufactures started making those upgraded hand controllers. So if you have an old one with RS-232 port just upgrade the hand controller. It will save you a lot of stress, believe me.

Before You Connect Telescope To Computer

Before you hook up the telescope with your laptop, you need to set up the telescope first. And by that, I mean that you have to star-align the telescope properly. You can’t connect it before that because it will not work. The telescope needs to be set up first, and you have to go through the star alignment with your hand controller. After you do that and it is working and tracking properly, you can bring your laptop and the cable.

Connecting Telescope To Stellarium

This process is straightforward, and you will be connected in a few moments. When you start the Stellarium, go to the configuration window and click on plugins. We need to load the plugin first. On the left side of the window scroll down and search for Telescope Control. When you click on it, you will see that the Configure button is gray and is not clickable. It is because the plugin is not loaded. Tick the Load At Startup box and restart the Stellarium.

Now the plugin is loaded so go ahead and find it again, and you can now click the Configure button. The telescope window will open, and it will be empty. Now press “add” button and another window will open with settings.

Leave everything as is and go to the Telescope properties. Here you can change a name and chose a device model in the drop-down menu. Pick the manufacturer of the telescope you have. It can be Celestron, Sky Watcher, Meade or other.

Click OK, and you will see your telescope in the list now. Hit the Start/Connect button to engage the connection. A small rectangle will appear on the sky map. This is the position where your telescope is pointing on the sky now. To initiate the movement of the telescope, find an object you want to go to and click on it with the left mouse button. After it is selected, hit Control+1(Windows) or Command+1(Mac OS X) and the telescope will automatically slew to the position of the object. You will also see the rectangle moving across the map as the telescope is slewing to the position you picked in Stellarium.

How To Connect And Control The Telescope With SynScan Pro App

Using the Stellarium is an easy way to control your telescope, but if you have SynScan GOTO mount, you can get more control over the telescope using a free app from Sky-Watcher called SynScan Pro. It allows you to control your telescope with your smartphone, tablet or PC. You can download the app here. And here is the video I made explaining how to connect it. I will be very happy if you subscribe to my youtube channel because I will be doing a lot of interesting videos about the telescopes for you.

How To Connect And Control Celestron Telescope Remotely

If you have a Celestron telescope, then you can control the telescope remotely using the SkyPortal WiFi module. You can read more about this method in my other article where I explain how it works HERE.

What is ASCOM?

You don’t have to know this if you are a beginner but it is a part of connecting the computer with a telescope, and you may find this term later on when pursuing this hobby, so it is good to explain it now. ASCOM is short for Astronomy Common Object Model. It is used to connect a variety of the telescope equipment to different software. Trying to explain it simply is hard, but I love the explanation by Dylan O’Donnell. He has a Masters of Information Technology, and NASA and ESA have featured his astrophotography, among others. He is also a member of Team Celestron where he also contributes. To date, two of his images have been selected for NASA Astronomy Photo of the Day (APOD). If you want to know what is ASCOM, watch this video:


Controlling your telescope from your computer is a very convenient way how to do skywatching. I love the way how I can point the telescope anywhere on the sky in seconds, and I don’t have to type the object name on the hand controller. It is also helping me to know what can I see from my position in real time and based on that, plan my session. It is also perfect during freezing nights when I can sit inside, nice and warm, and my telescope is outside in the cold. Seriously, it is amazing because you don’t want to be sitting outside when it is -15°C. So, I hope that you will be successful with connecting your telescope with a computer and I wish you Clear Skies!

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