Monday, October 12, 2015

Dark night out with the Bubble Nebula and my new QHY5L-II

Finally had a chance to image in some dark skies last night! A sudden break in the rain prompted a last-minute observing session at the NASA Skywatchers dark site, on a holiday weekend no less. It was nice to see the dust lanes of the Milky Way again and man the stars were bright! I've been imaging out of my driveway all this year while settling in with a new youngster so it was a treat to see the real night sky.

Despite some guiding challenges, I captures just over 2.5 hours of eight minute subs of the Bubble Nebula and neighboring M52. Here is a first look without darks, bias or flats and just a quick 20 minute processing. Not bad for a night’s work! I plan to capture another 2 hours at least on this object at the Staunton River Star Party next week to really drive it home.

I am happy to report that my new QHY5L-II autoguider worked exceptionally well. The sensitivity is noticeably higher the SSAG so I had plenty of guide stars to choose from. Plus, no horizontal banding noise like my SSAG. Did it improve my guiding? Well not entirely. Most if my concern is high frequency movements at every guide cycle. I was able to tame the declination oscillation by reducing the dec aggressiveness and increasing the min motion. Similar adjustments in RA only helped so much; there was still a lot of wiggling going on even with an east heavy bias and guide exposures of 2 seconds. I am now wondering how the quality of my guide scope impacts the guide star centroid calculation. I’ve always noticed a halo around stars in that scope so I wonder if that is a factor. Some more troubleshooting I suppose. Autoguiding is a finicky thing.

In the meantime, gear is packed for the Staunton River Star Party this weekend...clear skies are in the forecast.

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