Thursday, May 18, 2017

Why I love Video Astronomy

I live in a small town in Indiana (pop. 30,000 on my side of the river; the community across the river is around 70,000) 65 miles from anywhere, and surrounded by corn and soybean fields. Seeing conditions can be challenging, with big temperature swings between summer and winter. The dominant pattern for seeing is usually very transparent and very unsteady in winter and steady and hazy in summer. Add to that a lot of brightly lit car lots across the river, and you get much more light scatter than you would expect for a community of this size. My town is working with the Dark Skies people to improve lighting, and there is a definite improvement. However, our neighboring town is still swamping the skies with light.

Visual observing of DSOs is very challenging in these conditions, and that is where imaging comes in. Electronic imagers allow you to subtract out much of the light pollution and to see faint objects and detail with small apertures that would be impossible for the eye to see, even with large scopes.

The issue is that such images usually require high quality telescope mounts, long exposures, and long post-processing routines.

But there is a solution--video astronomy. Astronomical video cameras offer unparalleled sensitivity at the cost of resolution (the bigger the pixels, the more sensitive they are). But if you want to see DSOs in "real time," it's a great solution.  Some people modify low-light security cameras for this purpose, but my favorite cameras are hand-made by a Canadian company--Mallincam. They are a work of love and Rock Mallin, the founder owner of the company, is a true genius, using novel circuitry and exotic materials like aerogel to produce cameras that set the standard for 21st century video imaging.

Here's a result I obtained last night of the Whirlpool using a 6 inch Ritchey Chretien scope with .5x focal reducer and a Mallincam Xterminator II camera. This is a live stack of 4 x 15-second integrations at gain 0 (not shown, but 10-second integrations worked well, too). I have seen imagers use gain to get similar images with 2-second integrations (!), but I wanted to keep noise down. Skies were Mag. 2 and very hazy--just a few of the brighter stars visible, with passing clouds.



If you want to see DSOs in close to real-time and are frustrated by poor sky conditions, video astronomy is worth a look!