Table of contents for ATM
- Playing Galileo on a Friday night
- Second week of amateur telescope making
- Third week of amateur telescope making
- Fourth week of amateur telescope making
- Finishing up the polishing of my telescope mirror
- Really wishing my telescope was finished right about now
- The zen of telescope making
- A triumphant telescope-making turnabout
- Slow and steady wins the telescope-making race
- And the mirror figuring goes ever onwards
- Week ∞ of amateur telescope making
- Mirror-making breakthrough!
- Progress on my telescope’s mount
I’ve been working on a telescope for the past two months. I’m in the final figuring stages right now, which entails a repetitive cycle of a few minutes of light polishing followed by a Ronchi or Foucault test to see how the figure has adjusted. I’m aiming for a perfect paraboloid. I was oblate coming into figuring (my previous stroke was too short), but in the past two weeks, I managed to get it to spherical, then onto nearly paraboloidal. My only problem is that the center of my mirror is a little too low right now, so I need to work that. We did make a new, softer pitch lap (by adding a bit of turpentine to the mix), and that has helped immensely.
I’m really wishing my telescope was finished now, though. In case you hadn’t heard, Comet 17P/Holmes recently experienced an eruption/outgassing, brightening from a dismally dim magnitude 17 to magnitude 2.8, which is easily visible with the naked eye. I went out to take a look at it earlier tonight — it was amazing. It appears to be the third brightest object in the constellation Perseus, but just looking at it, you can instantly tell that it’s not a star because it has a fuzzy, rather than pointlike, appearance.
Unfortunately, the only optics I have available to me right now are a set of 8×30 binoculars (that’s 8X magnification with 30mm objective lenses). They’re not much better than the naked eye. Yes, they do allow me to see slightly fainter objects, but the comet doesn’t exactly present that problem. It’s easily visible to the naked eye. And the binoculars are really old. They have some sort of collimation problem, such that even though they are 8X zoom, I really can’t see objects any better looking through them. So you see why I’m looking forward to finishing up my 8″ telescope. It’ll be too late to see this comet by the time I’m done, but I should be ready for whatever the next unpredictable bright night sky object happens to be. That’s the beauty of astronomy: it’s so totally unpredictable. You just have to be ready to take in the sights.
If you haven’t gone outside to look at this comet yet, I really do recommend it. You can see it with the naked eye even in polluted urban environments. Just go outside after dusk and look towards the northeast. You don’t even need to be familiar with what the constellation Perseus looks like. Just look for the only fuzzy bright object in the sky and you can’t miss it. And you don’t want to miss it. Night-sky-gazing can be a near-religious experience.