Wednesday, January 24, 2018

LOTS More Herschels, But Not All At Once

I've had a few nights that were clear enough for imaging and with out a moon to interfere. Over the course of two nights, I managed to image 51 Herschel objects and one Messier object. As it turns out, a lot of the Herschel objects are open clusters. Fortunately, my scope has a pretty good (much better than most, I imagine) GOTO, and has found all of the 52 objects quickly, allowing me to image that many in such a short period of time. At least, I think I have 52 objects. How will I know? Well, that's a fair question. So I thought I would give an example using one method I use to verify what I have imaged.

NGC129 in Cassiopeia

This is my image of NGC 129 in Casssiopeia. At least, that's what I think.

MegaStar version of NGC 129. Yellow rectangle is what the camera shows.
This is a screen shot of my star mapping program called MegaStar. It provides a fairly accurate representation of the stars, planets, and deep sky objects like open clusters, galaxies, and nebulae. This shot shows the stars to about magnitude 16, which is very, very dim stars. My image shows stars to an even dimmer level, but this is sufficient to check where I'm pointed. Actually, it's fairly confusing to go this “deep” (meaning showing so many dim stars).

NGC129 fewer stars to show patterns better.

NOTE: PLEASE DON'T SCROLL BELOW THE FOLLOWING PARAGRAPH UNTIL AFTER YOU HAVE READ IT.

This is the same image as above, but I changed the lower limit of star brightness to magnitude 12.4. There are now fewer stars to compare to my image, and those stars are brighter. Just for fun, can you make the comparison between the my image and the above image to see that they are showing the same stars? Take a minute and try. I'll give you a hint; it's just pattern matching. (Try looking around the number "129".)

NO PEEKING!!! :)

Both images, showing matching areas. Can you see the matches?

OK, now a side by side comparison, but with six different areas shown where the pattern of stars match in both the Megastar image and my image of the sky. I usually don't try for only one matching pattern, but several, at least two. That way, I'm pretty sure I have correctly identified my target object.

NGC7789, also in Cassiopeia. Cluster is basically in the center of image.

For something a little different, and while I continue processing and verifying other images, I decided to take a color image of one of the objects, NGC 7789, also in Cassiopeia. Two things to note about the image : 1) the color image is much nicer on the eyes than the black and white images that I'm using for identification and hopefully you can see that there are blue, yellow, and red stars in the cluster (which is in the center of the image) and 2) since 7789 is in Cassiopeia and the Milky Way runs through Cassiopeia, there are a lot of other stars than just the cluster, making it more difficult to tell which stars are part of the cluster. This identification has been verified as well.

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