COSMAN ASTRONOMICAL OBSERVATORY – A Dream Realized

 Building an observatory has always been one of my dreams, and I’m proud to say it’s now a reality. The COSMAN ASTRONOMICAL OBSERVATORY is a homemade project, born from passion, recycled materials, and long nights of learning, assembling, and testing.

The main structure is built from bricks and concrete, providing solid support and insulation for my instruments. For the dome, I took inspiration from modern telescope enclosures like those at La Silla Observatory in Chile, but added my own touch using wood and a rotating base. The dome is currently manual, but I plan to motorize it in the future.

Inside the observatory, I use the Altair 70/420 ED doublet telescope. It is compact but powerful, perfect for wide-field astrophotography. Attached to it is a Canon 500D camera with the IR filter removed, which improves its sensitivity to deep-sky objects such as nebulae and galaxies.

For the mount, I use a custom GoTo system using a 3D printed body and NEMA stepper motors. The electronics are driven by an ESP32 microcontroller, connected to A4988 stepper drivers through a custom shield. The mount runs OnStep, an open-source software made for amateur telescope control. It communicates with ASCOM, which allows integration with the excellent NINA software.

Through NINA, I can manage everything from taking pictures to correcting the mount's position through plate solving. ASTAP plays an important role in this process, making solving accurate and smooth, even in my Bortle 6 to 7 sky conditions. For autoguiding, I use a modified Logitech C170 webcam combined with a 50mm f/1.8 lens. This setup works well when there is a bright star in the field, usually brighter than magnitude 4.

Recently, I started testing a PS2 Eyetoy camera (Namtai version) for autoguiding. It appears to be more sensitive in low light conditions. For those who want to try it, remember to install the driver in Windows Test Mode, since the driver is unsigned on Windows 10. I am pairing it with the same 50mm f/1.8 lens to compare its performance with my current autoguider.

At the moment, the observatory does not have an all-sky camera, and the dome rotation is still manual. However, I plan to continue upgrading it step by step. I strongly believe in learning by doing, and each improvement takes me closer to a fully automated observatory.

If you have any suggestions or feedback, I would be very happy to read your comments and ideas. Astronomy is a beautiful journey, and this observatory is just the beginning.

Clear skies!