March 27, 2010

First Light with the AT8RC and ...

... announcing that my EM-10 guides very well at 1300mm. Well, maybe. This was a test shot to see whether I could image with this scope without having to buy a new mount. It looks like I might be able to. There are all kinds of problems with this image. I forgot to check collimation before setting up, I took no flats and they are obviously needed, and the colors are skewed toward the red. Also, last night the moon was 89% full, and the sky was full of water vapor (transparency was lousy). It was a good night to test out guiding. I wanted to know if I could shoot with the AT8RC on the EM-10. I'd say maybe. The star shapes in the image are, I believe, a result of miscollimation of something in the optical path; the shapes stayed the same no matter how long of an exposure I took, and they are uniform in each sub-exposure. The guiding was spot on. Actually, the mount put in the best guiding performance I have ever seen. At any rate, it looks like the scope, mount, and focal length might work for me, and that deserves a post. In fact, there was a light breeze; more wind than I've ever imaged in, and it didn't show up in the image at all. Guiding was done with a 60mm f/4 homebrew scope, a DSI Pro Mono, and PHD. The 1300mm focal length was reached by adding a WO 0.8x II ff/fr in front of the SXVF-H9C. The telescope's natural focal length is 1625mm.

The first image is shrunken down to de-emphasize the funny star shapes. The second image is a 100% crop of the galaxy cores.
Here's a full-sized, bluer version, processed a different way:And here's a version pre-processed in Nebulosity and stacked and otherwise processed in Maxim DL, with finishing touches in Photoshop CS3:

March 20, 2010

M13 (3-18-2010)

It was 4 am. M101, which I had been shooting, was crossing the meridian. I could flip the whole scope around and shoot another 2 hours on M101, or I could quickly move the scope over to something just emerging from the trees and take two hours on that. It would have to be something I could find easily, as I was pretty tired. So, here again is the object I've practiced most on: M13.

To do something interesting, I took 10-minute subs. There is some flexure between guidescope and the 80ED, and you see it in this image as slight flaring on the bottom left of each star. It's not much, but it's clearly something to worry about. However, the 10-minute subs gave a much better histogram (all colors moved off the left side) than the 6-minute subs I used for M101. The SXVF-H9C needs at least 10 minute subs, I think, which means I either have to guide off-axis or get a better guiding system.

This is 13x10' through the ED80 with the WO 0.8x II ff/fr, Celestron LPR filter, guided on the Tak EM-10 with a DSI Pro through an AT66ED. Processing was done in Nebulosity and PS CS3.

Here is a smaller version. Shrinking the image makes the guiding error less noticeable:

March 19, 2010

M101 & First Light with New (Used) Camera

Here is first light with the SXVF-H9C, a new (used) camera I was able to purchase. This is 40x360" through the ED80 with the WO 0.8x II ff/fr, guided on the Tak EM-10 through an AT66ED and the DSI Pro with PHD. Nebulosity 2.0 was used for capture, and Nebulosity, Photoshop CS3, and Maxim DL were used for processing.

Actually, 6-minute subs were not long enough to capture what I could of this, so when I finished processing, I did some more stretching to see what I missed. Here is a B&W that tells me some of what to look for next time:

March 16, 2010

Atik's Imaging Contest

I entered my NGC 1491, Pacman, and Bubble Nebula images in Atik's 2010 imaging competition. The link to the competition is here. My images are in section 1 with all the other little cameras. These were the three best images for me in 2009, so I'm happy to see them posted forever (I hope) with those of some very talented imagers. Of course, the large format images in Section 3 steal the show. Enjoy.

March 3, 2010

NGC 2419 (3-2-10)

This globular cluster is so distant from the Milky Way that it was once thought to be unconnected to any galaxy. But it is bound to ours after all. NGC 2419 is about 300,000 light years away, not nearly as far as Palomar 4 at 360,000. The furthest globular out that we know of is AM 1, which is nearly 400,000 light years away. NGC 2419 is the 5th most distant from the sun. Source.

NGC 2419 is close enough and large enough to look like a globular through my little scope and camera, however. My little scope goes pretty deep, actually. Here is the same image blown up:
And here is the blown-up image labeled with a few magnitude numbers:
As you can see (well, you might have to turn the lights off to see some of those little stars), my little image actually shows many stars from the cluster. I have determined that the dimmest individual star I can pinpoint in my image is magnitude 19. Of course, some very dim stars register differently in my equipment than in the survey used for magnitude measurements found at And it's possible that a variable star was brighter on the night I took my image. Still, mag 18 stars aren't bad for two hours with an 80mm scope from the suburbs and the 90% full moon rising roughly 90 degrees away. A good comparison image (and the best image I know of NGC 2419) is here. Also worthy of mention (prettier but smaller).

The slightly odd star shapes in the image are caused by flex in the optical path. I have found the problem now, I believe.

Imaging Scope: TMB80CF (80/504)
Imager: Atik 16
Exposure: 36x200" (the top image) & 26x200" (the enlargements)
Filter(s): Astrodon Gen II L
Capture Software: Nebulosity 2
Mount: Takahashi EM-10
Guiding Camera: DSI Pro
Guiding Software: PHD
Guiding Scope: AT66ED
Date: March 2, 2010
Location: The Woodlands, TX
Processed with Nebulosity 2, Maxim DL, & PSCS3