M101: First Light with William Optics Pleiades 111 Telescope “Blue”

It’s a well-known astrophotography curse that buying new equipment means weeks, if not months, worth of cloudy skies.  My new telescope, a William Optics Pleiades 111, a 11.1 cm/4.37 inch diameter refractor that I’ve nicknamed “Blue”, was no exception.  It took about a month after I got the telescope (and the additional two counter weights I needed to balance it) for the skies to at least somewhat clear.  I got everything set up, just to watch the clouds roll in.  Happily, they then rolled back out.  And then rolled back in.  And out.

I ended up with enough data to make a first light picture, but I’ll need to collect more data for a final image.

I had contemplated what to image for first light.  Since the telescope name is Pleiades, the Pleiades would have been a good target, except they’re currently barely above the horizon at sunset.  My favorite nebula, the Orion nebula, would have been a good target, except it’s also currently barely above the horizon at sunset.  It’s “galaxy season,” so I decided to image a galaxy.  I’ve imaged M101 before because it hosted a supernova in 2023, so it gave me a good point of comparison.  

The comparison isn’t entirely a fair one.  On the one hand, this is an entirely new setup, with a much larger diameter telescope, an astro camera instead of a consumer camera, and a guide scope and guide camera to better control the tracking mount.  Additionally, I’ve picked up a lot of processing skill in the last two years, such as using shorter images for the stars so they don’t “bloat.”  On the other hand, this was 3.4 hours of galaxy data from my Bortle 7-8 light polluted driveway instead of 10.6 hours from the Bortle 2-3 dark skies of Dell City.

Because of the light pollution and limited imaging time, there is a lot more background noise in the new image.  But the stars are enormously improved from the old image.  And there is more detail in the new image.  I can’t wait to see how an image with more data turns out!

Once the clouds roll away again ….

Camera geek info May 9, 2025 (new image):

  • William Optics Pleiades 111 telescope
  • ZWO 2” Electronic Filter Wheel
  • Antila RGB filters
  • Blue Fireball 360° Camera Angle Adjuster/Rotator
  • ZWO ASI183MM-Pro-Mono camera
  • William Optics Uniguide 32MM F/3.75
  • ZWO ASI220MM-mini
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames (new image):

  • May 9, 2025
    • 32 30 second Gain 150 Red lights for stars
    • 24 30 second Gain 150 Green lights for stars
    • 22 30 second Gain 150 Blue lights for stars
    • 53 60 second Gain 150 Red lights for galaxy
    • 66 60 second Gain 150 Green lights for galaxy
    • 86 60 second Gain 150 Blue lights for galaxy
    • 30 0.2 second Gain 150 Red flats
    • 30 0.1 second Gain 150 Green flats
    • 30 0.1 second Gain 150 Blue flats
  • Darks, Flat darks from library

Camera geek info (old image):

  • William Optics Zenith Star 73 III APO telescope
  • William Optics Flat 73A
  • Canon EOS 60D in manual mode, 2 minute exposure, ISO 1600 and ISO 2000, custom white balance 3500K
  • iOptron CEM40
  • Dell City, Texas Bortle 2-3 dark skies

Frames (old image):

  • June 10, 2023
    • Run 1 1600 ISO
      • 99 2 minute lights
      • 31 0.01 second flats
      • 20 0.01 second flat darks
    • Run 2 1600 ISO
      • 39 2 minute lights
      • 31 0.02 second flats
      • 30 0.02 second flat darks
      • 71 2 minute darks
  • June 11, 2023 2000 ISO
    • 151 2 minute lights
    • 31 0.02 second flats
    • 20 0.02 second flat darks
    • 31 2 minute darks
  • June 12, 2023 2000 ISO
    • 30 2 minute lights
    • 31 0.02 second flats
    • 30 0.02 second flat darks
    • 32 2 minute darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

Spectacular Comet C/2023 A3 Tsuchinshan ATLAS Image Collection

Last fall, the spectacular Comet C/2023 A3 Tsuchinshan ATLAS looped around the sun and put on a show in the early evening sky.  I had a great time having a comet tailgate party with friends, seeking it naked eye, and capturing it with my camera and an 85 mm lens.  

As the days passed and the comet travelled away from the sun, it grew dimmer and its tail grew shorter, and I switched over to using my telescope.  In the left-most of the lower images, you can see some interesting structure in the comet’s tail.  

Processing comets is a challenge because the comet moves relative to the stars and so has to be aligned and processed separately.  They take longer to process than other Deep Space Objects, and I only just finished processing all my images.  I thought it would be fun to collect them all together and make the picture above.

Imaging this visitor from the outer solar system was a great treat.  I’m looking forward to the next one.

Sh2-274 Abell 21 Medusa Nebula

Sh2-274 or Abell 21 or the Medusa Nebula is a planetary nebula – the gases expelled from a red giant star before it becomes a white dwarf, lit up by that star.  It’s located in the Milky Way, approximately 1930 light years away, and it has an apparent size of 10.25 arcminutes, making it 5.75 light years across.  Given the amount of time it would take to reach that size, it is considered to be an “ancient” planetary nebula.  

I find these small nebulae beautiful and fascinating. Each has its own unique structure.  This one has a Ha rim and an Oiii interior and has filaments (the filaments are probably the source of its nickname, the Medusa nebula).

In this image, the stars came from images using red-green-blue filters, and the nebula came from images using Hydrogen alpha (mapped to red) and Oxygen iii (mapped to blue) filters.  The nebula was processed separately from the stars to maximally enhance it.

I had hoped to get enough data on this one the last time we enjoyed the dark skies in Dell City, Texas, but there were a lot of high clouds that limited the amount of data I collected there.  So I collected more data from my driveway at home until I had almost 7 hours of Ha data and 6.7 hours of Oiii data.  

Camera geek info – Narrowband:

  • William Optics Zenith Star 73 III APO telescope
  • William Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila HO and RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies
  • Dell City, Texas Bortle 2-3 dark skies

Frames:

  • January 24, 2025
    • 14 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • February 15, 2025
    • 100 30 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
    • 98 30 second Gain 150 Green lights
    • 30 0.02 second Gain 150 Green flats
    • 60 30 second Gain 150 Blue lights
    • 30 0.02 second Gain 150 Blue flats
  • February 20, 2025
    • 19 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
    • 5 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • February 21, 2025
    • 68 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
    • 30 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • February 22, 2025
    • 48 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
    • 32 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • April 7, 2025
    • 131 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • April 8, 2025
    • 130 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • April 10, 2025
    • 72 60 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • April 11, 2025
    • 133 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • April 12, 2025
    • 137 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • 30 Flat Darks from library
  • 30 Darks from library

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • NBColourMapper
  • Generalized Hyperbolic Stretch