Wednesday, July 19, 2017

Test of outreach system

I'll be doing a public outreach event for our local Niches Land Trust next month at a dark sky site about 8 miles out of town (actually the site where my old observatory runoff shed still stands). After getting some good advice from the experienced folks on the Mallincam Yahoo Group, I decided on the following setup:

  • Mallincam 8 inch f/3.9 newt astrograph
  • Mallincam Xterminator II camera
  • laptop, projector, and screen
One of my concerns about the Xterminator II is that, while it is very sensitive, it has a limited FOV. I was worried that GOTOs would not put objects on the imaging chip and that I would be fiddling around a lot. In my tests last night, I only ran into this problem twice and it was easily fixed with a quick adjustment with the finder scope. Otherwise, I found every object, even those widely separated that required long slews.

The Xterminator II tradeoff is that its high sensitivity comes with relatively low resolution. While that's not good for pristine images, it gives fast (typically less than 10 seconds), colorful images that are perfect for public outreach events. 

In this first image, I stacked 5 x 9 second exposures (averaged, not additive). The result is a pretty decent image of the Whirlpool in an urban sky (note that I did not have the imager as orthogonal as it should have been to the focal plane--hence the elongated stars).

For comparison, here is a single, 9 second integration:

What's also interesting is that I captured 2 other galaxies in this image, IC 4277 and IC 4278. Their magnitudes are 15.7 and 15.4 respectively--not bad for a 9-second integration under hazy, light-polluted skies!

I also imaged M3, M13, M92, and the Wild Duck Cluster. These images were all taken with 5-second integrations. These kinds of images will, I think, work well at a public event, especially as it takes only a few seconds to capture them. Add to this a decent dark sky, and the results should be pretty decent.



Wild Duck Cluster