May 22, 2010

Seeing Stars and Clouds

Tonight clouds were few but present, so I took the modified DS-10 mount out for a spin with the 4" achromat. To counteract the fluctuations in the house current, I hooked up an Accutrak drive controller in between the AC outlet and the mount. This seemed to keep the drive steady. Even at 120x I noticed no movement so long as the scope was properly balanced.
First, I found Vega, then Epsilon Lyrae, which was split nicely at 120x, with black in between the tight doubles when seeing would permit. Next I looked briefly at M13, then at Antares, then up to M10 and M12. These latter globular clusters are relatively nearby. M10 is but 14,300 light years distant, and M12 just 16,000. Both shine less brightly than M13, which is over 25,000 light years away, which shows just how large and bright M13 is. After M10 and M12, I moved down to M107, which is much dimmer still, and barely visible in the 4" near my light polluted horizon. M107 is 21,000 light years away.
Two more targets: Izar, in Bootes, which was split at 120x, with the second star appearing tangent to the first diffraction ring, and roughly north, of the brighter star. Izar is always something of a thrill to split in a smaller scope because it does not appear double till one is nearly in focus. Only at perfect focus is the star clearly there. I found the primary to be white orange and the dimmer star a gray green.
Finally, I took a brief look at Saturn before the clouds moved in more fully. I saw only two moons, but the shadow on the planet was crisp and dark.
Then the clouds moved in.

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