Supernova remnants: Autoguiding & the SpaceCat

veil nebula redcat 51

First light with the new SpaceCat / RedCat 51 telescope was a tough choice. The wide 250mm field of view is perfect for capturing complete views of so many deep-sky objects. But with the Milky Way setting earlier now, the Veil nebula in Cygnus was the perfect choice.

After a few failed attempts I found the right settings to get the new ZWO ASI120MM-S guide camera connected to the AstroTrac TT320X-AG mount, to finally start autoguiding with PHD2 and N.I.N.A. The resulting 5 minute sub images with pinpoint stars and dithering enabled makes a world of difference. Capturing so many more photons with the faster scope and longer exposures made for an easy set of images to work with.

I absolutely love the near 3D look of the ionised gasses in the nebula. The intricate details in the Western Veil in particular are stunning see in detail.

I still have some tilt issues going on with the D5500 camera sensor which I’ll need to dial out (the left and right hand sides are out of focus). A quick 30 second exposure with the old D7000 confirmed it as an issue with the camera and not a fault of the telescope. The new scope itself is incredibly sharp and lives up to its reputation as a fantastic little quadruplet astrograph.

Image details: Modified Nikon D5500 and William Optics SpaceCat 51 250mm / f4.9. Total of 2 hours and 20 minutes of exposure time (28 x 300 seconds) at iso 100. Using Optolong L-eNhance filter. Tracked with AstroTrac TT320X-AG. Guided with ZWO ASI120MM-S guide camera and Orion 50mm guide scope. Stacked in Deep Sky Stacker with 12 dark / 30 flat / 30 bias frames. Sequenced with N.I.N.A.. Edited with Photoshop and Starnet++

  1. declan Reply

    Hi Noctilove
    I think the shots you took with your barn door tracker, are quite amazing and inspiring. For example the whirlpool galaxy, I did not think that was possible with a dslr. I am trying to build your barn door tracker, I modelled it as an isosceles triangle. With an M8 bolt of 1.25 mm pitch, I calculated that the pivot to hinge distance should be 286mm but in your design drawing you have given 274mm. Is this because your design is not an isosceles triangle, is the 274mm distance correct?

    • Nick Reply

      Hi there. Great to hear the site helped inspire you to build your own tracker. It’s been a long while since I worked on it, and your distance of 286mm could certainly be correct. If that’s what your calculations show then I would say go with that. Theoretically any distance should work as it all depends on how fast you rotate the handle. Using the adjustable timing beeps method instead of mirroring the motion of a second hand of a clock face should allow for complete flexibility in the design. You can adjust the beep timings (handle rotation speed) to suit whatever size you made the tracker, as well as whatever bolt size is used. Hope this helps. Good luck with the build! Feel free to upload any results you get to this site if you’d like to share them, it would be great to see – Nick

  2. declan Reply

    thanks for that. that is helpful.

  3. declan Reply

    i like your idea of adjustable timing beeps. it means you have the ease of construction of a manual driven tracker, but you can make it as accurate as an algorithm driven motor.

Leave a Reply