Celestial hemisphere:  Northern  ·  Constellation: Canes Venatici (CVn)  ·  Contains:  M 94  ·  NGC 4736
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M94 (Cat's Eye Galaxy), Ben Hayes
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M94 (Cat's Eye Galaxy)

Getting plate-solving status, please wait...
M94 (Cat's Eye Galaxy), Ben Hayes
Powered byPixInsight

M94 (Cat's Eye Galaxy)

Equipment

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Acquisition details

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Description

I wanted to image this target on moonless nights in February and March, but it was always cloudy.   In early April, we finally had two clear nights with stable atmosphere, so I went ahead despite a waning gibbous moon that averaged 77.2% illumination during the imaging session (April 9 and 12, 2023).   Considering how bright the skies were, guiding was decent (0.63” or 0.61 pixels total RMS).  Out of over 130 light frames collected, I deemed 95 worthy of stacking into a final image.  GraXpert did a great job remove the gradients - its kriging algorithm is great at removing sky glow and the new AI version is phenomenally good.  Color correction was done using PixInsight’s SPCC. which I also find amazing.

The stars are very big in this region - this image had a full-mean half-width (FWHM) of 7.182 pixels and eccentricity (Ec) was 43.4%.  Ec values greater than 40%  exceeds most people's threshold for round stars, but BlurXTerminator helped improve their shape.  The "raw" linear version of this image right out of PixInsight's WBPP program is shown below.   During Weighted-Batch Pre-Processing (WBPP) the subframes were drizzled 2x.  During post-processing, the stacked 2x-Drizzled image was then reduced 2 times using PixInsight's "Geometry/IntegerResample" process.  So the FWHM and Eccentricity values reported here are for the raw image data from the ASI294 camera with a pixel size of 2.31 microns. 

Being a novice astronomer, I struggled to process this image in PixInsight, not so much with bringing out textural details in the galaxy, but keeping the colors tone to a muted tan (and not golden or reddish-yellow), with dark brown dust lanes and blue purple core, like in the Hubble images of M94.   Needless to say, I consider this image a "work in progress" and plan to come back to this galaxy next year.   Undoubtedly, 12-16 more hours of integration time will help immensely.    Also, when I took this image, I wasn't very good at collimating my SCT.  I'm still not very good, but over the summer months I've been able to fine tune it a little better. 

M92_FWMHE_Analysis.png

Comments

Revisions

  • M94 (Cat's Eye Galaxy), Ben Hayes
    Original
  • Final
    M94 (Cat's Eye Galaxy), Ben Hayes
    B

B

Description: Same as original (Revision A), but without the acquisition details.

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M94 (Cat's Eye Galaxy), Ben Hayes

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Cloudy Nights