20 Inch Dobsonian Telescope

By Tim Cowden

The Texas A&M Observatory has recently acquired a 20 inch Obsession telescope. Don Carona has graciously made it available for club use and outreach. This is a large Dobsonian telescope, and usually takes two people to set up and use. It is tall enough that a ladder is required to see through the eyepiece for anything half way up the sky. In spite of these minor obstacles, the view through the eyepiece is glorious.

A group of us, Tom, Joel, Karl and I went out to the observatory to help Don assemble and align the scope. We assembled the struts and put on the upper cage. The secondary mirror required some tweaking as well. A little rough collimation and we dragged the scope out into the full moon. The moon was blinding, but detailed. Star clusters, Albireo, the Ring Nebula. All this without a good finder. There was one on the club 10 inch telescope inside, but we forgot about that.

The next meeting was a new moon, and we hauled it out again, remembering to bring a Telrad finder. The best view for me was the Great Nebula of Orion, barely above the horizon. The glowing gas had detail I had never seen before. The effort to move the large scope in and out of the observatory building was worth it. A better scope cart is a project in the works.

There are a few problems that need to be addressed. One of the azimuth rocker laminate strips needs to be reglued. A good ladder dedicated to the telescope is needed and could be purchased with club funds. It might be worth purchasing some quality eyepieces and a finder for it as well. As the scope could be a big draw for outreach events, the investment in the scope accessories would be justified.

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