Baylor University Clear Sky Clock:

Saturday, August 12, 2006

Observing: Planetaries & Globulars in Cyg, Del & Aql, and the Moon

Alignment worked well tonight, pointed toward Vega and Altair in the correct direction. Didn't do anything differently this time. Go figure. Tested on M57 (center of field), M27 (toward edge), and M29 (out of field in TV Zoom @ 24mm). Best I can hope for without accurate polar alignment, I guess.

For tonight's target list, I picked a bunch of planetary nebulae and globular clusters in Cygnus, Delphinus and Aquila with help from the S&T PSA and NSOG:
  • NGC 6826: The Blinking Planetary, very bright. Damned thing actually blinks!
  • NGC 6905: Revisited this planetary after seeing it last time out. It's still there...
  • M56: GC, good view with LVW13
  • M71: GC, also good with LVW13
  • NGC 6760: GC, dim but visible
  • NGC 6934: GC, brighter but small
  • NGC 7006: GC, also dim
Several other objects on my list were not seen (NGCs 6842, 6894, 7008 and 7048); NGC 6891 was already in the tree by the time I attempted it.

By 10:30PM, moon glow washed out the sky. I set the Sirius for lunar tracking and waited for the big guy to rise from the trees in the east to try some DSLR imaging with the Digital Rebel and Celestron 40mm Plossl. After 11:30 I took a bunch of shots of the eastern limb around Mare Crisium; three came out OK (click any image to see larger version with craters labeled):



One big problem: All images grow out of focus radially from the center of the field, as if they were put through a Radial Blur filter in Photoshop. This is most evident in shots in which I placed the limb near the center of the field, thus offsetting the moon to one side:

I'm hoping that something in the imaging chain was not seated properly, perhaps the eyepiece in the Maxview DSLR adapter. Or maybe the combined weight of diagonal, Maxview, eyepiece and camera body was too much for the drawtube (which I probably did not have fully locked down) and caused it to shift out of line slightly. Whatever, I need to figure this out next time.