First Narrowband Difficult Subject Planetary Nebula Sh2-313 - Adam Lundie - Eatons Hill Observatory

First Narrowband, Difficult Subject: Planetary Nebula Sh2-313

10-May-2016
First Narrowband, Difficult Subject: Planetary Nebula Sh2-313 thumbnail
First Narrowband, Difficult Subject: Planetary Nebula Sh2-313
For my first foray into narrowband imaging, I have chosen a very dim & difficult target: planetary nebula Sh2-313, also known as Abell 35 and PK 303+40.1

This nebula shows a very distinct bow shockwave from the central star plowing through the excited oxygen. The central star is also spinning so fast it is close to tearing itself apart.

Image:

  • 33x 900s H-alpha bin2x2 + 10 flat + 50x dark + 120x bias
  • 27x 480s SII bin2x2 + 20 flat + 50x dark + 120x bias
  • 39x 420s OIII bin2x2 + 10 flat + 50x dark + 120x bias
  • Color Mapping:
    • Red: 67% Ha, 33% SII
    • Green: 67% OIII, 33% Ha
    • Blue: 67% OIII, 33% SII

Total integration 16 hours 24 minutes.

Hardware:

  • Celestron EdgeHD 1100
  • SkyWatcher EQ8 Pro Mount
  • Celestron 0.7x EdgeHD focal reducer
  • QSI 683-ws Camera @ -15C
  • Astronomik Typ 2c RGB filters
  • Orion StarShoot Autoguider
  • Foresight Innovations On Axis Guider
  • Starlight Xpress Adaptive Optics

Location:

  • Orange zone in Brisbane, Australia. (Bortle 7)
  • Imaged over 9 nights.

Software:

  • Planning & camera alignment with Aladin 9
  • Captured with AstroArt 6
  • Guiding with PHD2 + PHD_Dither
  • CCDInspector: Image analysis & rejection
  • CCDStack 2+: Calibrate, align, stack, flatten background.
  • Astra Image 4.0: Deconvolution.
  • Photoshop CC: Reduce noise, high pass filter, merge Ha+SII+OIII, color balance, curves, reduce gradient, saturation, minimum filter.

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