The End of a List

Last night two things happened that were quite enjoyable for me: 1) the grandkids got their first look through the telescope, and 2) I completed imaging the Astronomical League's Lunar List. The last two entries are below.

The grandkids got to see a few craters on the moon; specifically Copernicus, which was just off the terminator and was actually the best I've seen it. I should have taken an image of it, but didn't think of it at the time. They also got to see the really nice “star” Alberio. Naked eye we see it as one star. However, telescopically, it's two stars; one is blue and the other appears gold to me. It's a “goto” object to show people and I happen to really like it myself.

Well, here's the last two entries for me on the AL Lunar list.

Rupes Recta

Rupes recta, also known as the Straight Wall, is a linear rille (a fissure or narrow channel on the surface of the moon) that's about 100Km (about 62 miles) long.

Sinus Medii

Sinus Medii means Central Bay and, according to Wikipedia, is so called because it sits at the intersection of the moon's equator and prime meridian. Obviously, it's in the circle.

Herschel 400, The Beginning

At this very moment, there are no Messier objects in the night sky that I haven't seen or imaged. There is also very few nights when it has been clear enough to do either view or image, but on the nights that are clearer, I would like to have something to be looking for or at.

One of the usual lists that amateur astronomers start on after the Messier list (which is about 110 objects) is the much dimmer Herschel list. One of the lists, anyway. The Herschels found thousands of galaxies, nebulae, and start clusters that they put in their catalogs. The list of 400 was compiled around 1980 by a group from the Ancient City Astronomy Club in St. Augustine Florida. Since there is some overlap with the Messier catalog, including last night (the 18^th) I have imaged 33 of the 400. Of the targets that are not primarily nebula, I'm going to image them in black and white. So, last night I imaged about 10 in about an hour (actually 11, since one image contains 2). All from last night were either globular clusters or open clusters. All were in the constellation of Sagittarius, and are about ½ of the targets in Sagittarius.

For more information on the list and to know what's on it see

https://en.wikipedia.org/wiki/Herschel_400_Catalogue

Since Sagittarius is in the Milky Way, expect to see lots of stars and star clouds.

NGC6544 globular cluster

NGC6440 globular cluster

NGC6520 Open cluster. Notice dark nebula to left of cluster.

The dark nebula in image above is Barnard 86. The Barnard catalog is a catalog of dark nebulae.

NGC6522 Middle, NGC6528 to right, both globular clusters.

NGC6540 Open cluster (in the center)

NGC6553 Globular cluster

NGC6569 Globular cluster

NGC6624 Globular cluster

Two Twofers (two fors)

After diagnosing a problem with the Declination “transmission” in the scope, and subsequently deciding to do nothing about it, I tried some more imaging. I also found a potential problem with the Right Ascension as well, and that may lead to a disassembly and greasing of the part of the drive. We'll see.

At any rate, I tried imaging a “bright nebula” in the constellation of Vulpecula known as NGC6820. Some of these nebulas (or nebulae, if you will) have nicknames (ie, M17 aka the Omega Nebula, and 3 others as well) 6820 has none. It's a twofer because there is an associated open cluster, NGC6823; image one and you get both.

NGC6820 and NGC6823 (basically dead center)

NGC6820 is an emission nebula; hence, the predominately red color, and it lies about 6000 light years away.

The other twofer is two images of Saturn which shows the increased value of more frames (images).

Saturn, 200 frames

This image has only 200 frames (the images are taken as a movie and the the frames processed as though each frame is an individual picture), the best 75% were processed and used for this image.

Saturn, 2000 frames

This image used 2000 frames and the same processing. I think shows more detail and is clearer. What do you think?

Sun and Stars

This is sort of “how did the processing go” type entry. No real revelations, just making notes to myself, I guess. I'm pretty sure no one but me reads this anyway.

Three sun entries to start.

This was the sun taken September 7^th with interesting and very large sunspots. For the sun to be nearing a solar minimum, this is unusual activity. On the same day this was taken, IF I remember correctly, there were 5 coronal mass ejections recorded by NASA, one of which was headed toward earth and should have produced a nice aurora.

The sunspot kinda looks like an eye, doesn't it?

This image, taken on September 15^th shows a sunspot, and what I think is the beginning of a filament. A filament is, as far as I can tell, a flare or prominence that is seen “face on”, ie, coming towards us. Compare this filament to the prominence on the next image, taken the same day.

The most notable thing about this prominence, other than its giant size, is the detail. This is one of the more detailed images of the sun I have every gotten. I did things a little differently this time. I mounted the solar scope on the LX200GPS scope in the observatory. This allowed me to more accurately track the sun. Usually, I just put the solar scope on a tripod type mount with no tracking. The second thing I did was to make a slight change in the processing. The image file, which is a movie or .avi file, was 1^st processed in PIPP (a program, app to you younger readers, if any, that does planetary image pre processing; hence the name PIPP.) PIPP takes the .avi file and tried to arrange the frames (about 2000 in this case) so that any chosen interesting feature appears to remain steady, frame to frame. The chosen output of this is also an .avi file. This .avi file is then entered into another program call Registax, which takes the frames, aligns them, and then tries to stack them one on top of the other to form a single image, usually a .tiff file, which should have processing and image “noise” (seen usually as some type of graininess) reduced and hopefully the interesting part of the image a little clearer. Then “sharpening”, which tries to change the contrast pixel to pixel to make the image sharper (as well as other things like deconvolution) is applied to render the best, sharpest image possible. The change here was to NOT normalize the separate frames (try to make the histograms the same or similar) and apply the sharpening routine using the default setting rather than using the gaussian setting. Note to self, changing the step size to 1 from 0 also helped. I'm still not pleased with the overall clarity of the image; it's just that this is one of the more clear ones.

Also on September 7^th, I imaged other targets: M21, an open cluster and NGC6572, a very small planetary nebula.

M21

As is becoming usual for me, M21 is imaged in only the luminescent channel; so a black and white image.

Ngc6572. Blue dot is the nebula.

NGC6572, however, is a LRGB or full color image. The nebula is seen as a blue dot just above the center of the image. This image target is much more typical of what we would see in the night sky in terms of size and brightness. Most of the other targets I have imaged are of the “showcase” variety. The arrow in the image below points to the nebula.