Sunday, May 24, 2020

DIY GoTo system for dobsonian telescope


Hey people, hello from Illinois. (Edit 02162022: Below steps are described in youtube https://www.youtube.com/watch?v=EVcJwujkwUs)

I have an 8 inch Apertura Dobsonian telescope well purchased from High Point Scientific. Then I made a really nice simple method for pointing Dobsonian telescope to astronomical objects like the GOTO system. Using the method I could see 7 objects in ~ 30 minutes (M3,M5,M13,M81,M92, Alcor binary stars, Cyg-61 binary stars) without automation/motorization. All you need to build the tool is a tape measure, a duct tape, digital angle meter, and your phone.  If your telescope points to the right altitude (Y-axis coordinate of your object) and azimuth (X-axis coordinate of your object), then you can see the object. So, method is made of tools for pointing the telescope to the right altitude/azimuth.

Altitude:

The method uses digital angle gauge meter for Altitude. Basically the gauge sits on the telescope reporting the altitude within +- 0.1degree which is really good. Added note: the device has an arch structure at the bottom which helps aligning the device to a pipe. Since telescope tube is basically large pipe, the arch also helps aligning the device to the telescope increasing accuracy. On the surface of the telescope tube, rotate the device back and forth (like rolling a screw cap) until you get a sense that this arch structure and the telescope tube is aligned well. You can feel it with some experience. This step is not a required step. It will work just fine without the step.

Azimuth:

Then I made a website to enable using tape measures on the base of telescope for pointing telescope to the right azimuth.

 I provide screenshots of PPT slides about the system. The mobile website mentioned in the slides is
https://astronomy-dobsonian.s3.us-east-2.amazonaws.com/index.html

(source code)













With this tool, amateur astronomy became so much fun and easy hobby. I go out at weekend nights watching galaxies/clusters/whatever I want. Instead of the arduous work needed for star hopping, I watch them while listening to music, drinking my favorite soda ;)  

Also, stargazing became very social activity. Because the Push-To system finds objects very quickly, I can invite my friends. They can wait 1~2 minutes needed to find the object. I will be really hesitant to invite my friends, if I take more than 5 minutes to find objects using regular manual methods: too much pressure that I need to find it and I would get stress from the fact that my friends are waiting long time.  Due to this, I made more than 10 trips with my friends! 





4 comments:

  1. i like it. wonder if glow in the dark tape measure exists, would make this that much easier.

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  2. Excellent job on the blogspot. I use this method too.

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  3. The first telescope was unveiled in the Netherlands in 1608, made by Jacob Metius and Hans Lippershey. It was made famous, however, by Italian mathematician Galileo, who constructed his own, improved device and was the first to use it to explore space. With his telescope he discovered four satellites of Jupiter, and resolved nebular patches into stars.
    telescope
    telescopes

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