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M35 in action- an example of "integration"

"Integration" is part of the astro-video lexicon. Near as I can tell the result is about the same as taking a time exposure for whatever number of seconds. But what continues to astound me is what I see on the monitor when I use this feature of the Color Hyper MallinCam video camera.

This modest 80mm scope is showing me stars fainter than magnitude 14 when I do a 12-second integration with the Color Hyper MallinCam. To get an idea what this means in practice, take a look at the following animated GIF of the open star cluster, M35. It will open in a window of its own and change every five seconds, looping until you close the window.

Click here to see M35 animated GIF in separate, smaller window.

BTW - I wonder how many knowledgeable amateurs spotted NGC 2158 at the bottom of the 6 and 12 seecond integrations?

So why not use the most sensitive setting - 12 seconds - all the time? Same reason I don;t us emy largest scope all the time. As you go deeper - add more stars in this case - the perseption of an object changes. I used to always assume more was better - now that I have more, I know better ;-)

Besides, from an entirely practical standpoint the 12-second integration may bring up the background light too much, washing out an image. It is not always the best choice - but the truth is, I have a whole lot more to learn about how to best use this camera.

For the record:

M35 is an open cluster about 2,700 light years from us. It contains between 200 and 500 stars depending on whose count you accept.

NGC 2158 is a similar, but much more intense cluster of stars that is about five times more distant which is why it appears so faint on these images. I looked at M35 many times over the years without even knowing NGC 2158 was there. In these images it looks like a little cloud near the bottom.

The images were taken with the Color Hyper MallinCam mounted on the Orion Short-Tube 80 and using the focal reducer with 10-mm extension. The little scope was piggy-backed on the Obsession with ServoCat drive. The integrations are 2.1, 6, and 12 seconds respectively. Images were NOT stacked for the elimination of noise, but they were taken into PhotosShop Elements II where adjustments in light and contrast were made, and an unsharp mask was applied. Faintest stars visible in the 12-second integrations are below Magnitude 14 when you look at the jpeg versions below. The animated GIF in the separate window may not go this deep. (You cab click on the images below to get a somewhat larger version in a separate window.)

Posted by Greg Stone at November 22, 2006 04:28 AM Comments? Please email me: gstone@umassd.edu

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