Ad Astra Observatory

Cepheus is still a little low in the sky to get a full treatment. But I wanted to see what would happen if I shot an object that was low enough that the scope didn’t collide with the mount during the night.

I learned something very interesting. The mount has tracking problems outside of a certain “good” range. I had been starting my evening in this “good” range, and thus only getting a few good images at the beginning of the evening, with junk after that. Last night, I had some junk at the beginning of the evening, getting progressively better for awhile, then worse at the end of the evening. Very interesting. At least I have something to work with.

In any case, this time, instead of getting 4 or 5 out of 16, I got 8 out of 16 images (because I got the whole “bell curve”.

This is NGC 7635, The Bubble Nebula. The bubble is being created (from my understanding) by a Wolf-Rayet type star, which is apparently cranking out some serious solar wind and making a bubble in the surrounding nebula.

I just think it looks cool.

Here’s a closer view of the nebula core:

In each of these images (and most other images on my website, I followed my normal resizing pattern:
– for a “full frame” image, I crop to the largest 3×2 aspect ratio image I can

– for a “cropped” image, I crop to a 1500×1000 area
– either way, I then resize down to 900×600

900×600 is a nice size for the web, usually produces astroimages that are ~100k in size. Resizing down a little helps to “tighten up” the image, makes things look a little sharper, de-emphasizes the noise in the image, etc.

What I’m saying is that, generally, shots from Veronica can be as large as 1.3°x0.9°, but often I’m taking a 0.6°x0.4° chunk out of that. So far, with Pumpkin, I’ve always done full frame, because that’s sort of the point of a widefield scope. Pumpkin’s field is about 4.2°x2.8°. But because I do some cropping and resizing, the scale from image to image is not an exact 1:1 match to other images. The 1500×1000 -> 900×600 type images are all the exact same scale, of course.

My goal, instead, is to make the object as large as possible in the final image, while maintaining some kind of concept of scale.