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Open Cluster M93

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#1 Rustler46

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Posted 19 February 2020 - 11:45 PM

Here's a screen shot of the live stacked image:

 

M93 300X1-sec C-11- small.jpg

 

Observing Report:

  • Date and time of the observation = 2020 February 17, ~19:30 local time
  • Seeing & transparency conditions = fair seeing and transparency
  • Name of subject = open cluster M93
  • Hardware = AT115EDT triplet refractor, UV/IR-cut filter,  ZWO ASI290MC camera on G-11 mount
  • Software/process used for the live capture = SharpCap, 300 seconds via 300 1-second frames
  • Discussion of observations:
    Still getting used to how to use SharpCap for EAA. The bright stars in this open cluster made it much easier for SharpCap to find enough alignment stars. The building stack ended up looking like what you see. I not sure why the background looks different (blue) for the lower half of the image. But the cluster was interesting to observe, considering most of the stars are in the same volume of space, held together by their mutual gravitational attraction. It looks like it would have been beneficial to have used the atmospheric dispersion corrector (ADC), since the cluster was low in the sky. Perhaps this caused the blue/red fringes on opposite sides of bright stars.

Edited by Rustler46, 20 February 2020 - 06:41 PM.

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#2 clusterbuster

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Posted 20 February 2020 - 12:51 AM

Nice !

 Mark



#3 Rustler46

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Posted 02 March 2020 - 01:09 AM

Nice !

Thanks for your comment, Mark. This cluster is not one of the more spectacular ones, but is interesting nonetheless. Even the short (1-second) exposures brought out quite a few faint cluster members. Yet it looks like focus could be better. Still I find it fascinating to consider that these stars are held together in their location by mutual gravitational attraction.

 

For EAA clusters are good targets because the offer plenty of bright stars for SharpCap to align on. Also I recently discovered how the focus assist tool works for getting best focus on a single star. If there are enough bright stars, the multi-star focus assist variant is even better, since it averages the condition of focus of a collection of stars. An individual star varies a lot in FWHW due to seeing. But the average of a number of stars is much more stable. This I find makes achieving optimum focus much easier. Live and learn.

 

Best Regards,

Rusty




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