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Thursday, May 21, 2009

How to block the light pollution

This is the neodymium based 2" skyglow filter of Baader Planetarium. It's a good solution against the heavy light pollution of our suburban skies. I permanently use it for deep sky observations in Stuttgart(!) on my 21cm (f/11.5) DK cassegrain telescope with a 40mm eyepiece at a magnification of 60x (eye pupile 3.5mm). The Moon and Sky Glow Neodymium Filter does not affect the color of the stars. It also filters out the IR light. That's a useful piece of hardware.
Yesterday, I observed several deep sky objects in the galactic plane of the Milky Way using this filter:
  • M57 in Lyra: I clearly saw a ring of smoke. Really.
  • M56 in Lyra: a small globular cluster 30000 light years away.
  • NGC6871 in Cygnus: a small open cluster
  • NGC6888 in Cygnus: The cresent nebula. Yes, I saw its nebulosity.
  • M27 in Vulpecula: what a fantastic view! The sky background was black.
  • M71 in Sagitta Not as good as last year, because its altitude was too low.
  • NGC6905 in Dolphin: a small planetary nebula
  • M29: an open cluster in Cygnus
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Saturday, May 02, 2009

Round up your stars

This is just a small photoshop trick, how to make round stars, although your sources show an oval form. After duplicating the 1st layer, you shall apply the photoshop filter "Abdunklen" i.e. "make darker.." and move the duplicated layer with the cursor keys. That's all!

See how it looks like..