Feeling Crabby! ~ Astro-Mariner Observatory

Tuesday, February 17, 2015

Feeling Crabby!

February 17, 2015 Unknown

Despite not feeling particularly well yesterday, the forecast of no moon and a clear sky all night provided an opportunity to test out my new Altair Wave 115 refractor on a deep sky object that could not be missed. So, as the sun dropped below the horizon I started moving my gear outside and setting up for an imaging session. Once everything was setup and balanced correctly, I selected the Crab Nebula (M1) in Stellarium and slewed the scope to roughly the right location. I then used AstroTortilla to do a quick plate solving routine that established the accurate position of my scope and automatically re-centred on the right point in the sky - I love this software - so much easier than messing about with alignment stars.

Once it was dark enough to start a proper imaging run, I used Nebulosity 3 to instruct my QHY8L CCD to take 15 x 300s exposures, relying on PHD2 to accurately guide my scope through my Starlight XPress Lodestar camera and TS off-axis guider. I then retired indoors for a nice warm drink, where I was able to monitor the progress via screen sharing on my iMac. Once the session had finished I went back outside and packed everything away. I then went to bed - I wasn't feeling well after all.

The following morning, I reviewed the images and was pleased that only 1 image needed to be discarded. I then used Nebulosity 3 to apply the dark callibration frames to the 14 remaining images before stacking. The result was a relatively noise free, although faint, image of the nebula, but most surprisingly, was the flatness of the image compared to those I got from my previous scope - the Sky-Watcher Explorer 190MN Pro. With the exception of 1 corner, the stars seemed perfectly round across the image and there was no vignetting or background gradient at all. Application of Neil Heacock's processing workflow, using Photoshop CS6 and Noel Carboni's Astronomy Tools resulted in a very nice looking image, with a stunning array of stars and a lovely structure to the filaments of the nebula. Overall, a pleasing result from my new scope.