Monday, November 26, 2012

North Celestial Pole 3a

  I zoomed in on the pole a little more Saturday evening and was able to see more of the fainter stars near the pole. The bright star at the top of the image is Polaris, α UMi, and the brighter star towards the bottom center is λ UMi. If you look slightly above and to the left of Polaris you will see a small star and a much smaller companion which is an optical binary. Some of the stars just visible are approximately 9th magnitude.
  The second image is a merger of 6 images taken approximately 8 minutes apart. With greater magnification one has to be more careful about camera motion. If you look carefully at the rotational track you will see that one of the stars is out of alignment. It was not used to determine the center of rotation which is marked with a +.
  These images are approaching the limit of what one can do with a digital camera with 26X optical zoom. Magnification reduces the speed of the lens so longer exposure times or a larger aperature is needed. One could probably improve on the position of the pole by using zooming in more with a good telescope.

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