A little closer to Home

Well, the moon is getting fuller by the day,which sheds so much light on these humid skies that most of the deep sky stuff is basically invisible. So what's an astronomer to do, you ask? (Thank you for asking.) We look at the brighter objects. Mostly, that's solar system objects. I was hoping to get an image of Jupiter, but it turned out so poorly that I decided it was better to recycle the memory locations in the computer. It was BAD.

The moon was a different story, however. I imaged three areas on the 12^th, which meant I imaged with the terminator more easterly than I usually do; I usually start imaging around 1^st quarter. The reason is that the moon is over the roof of the observatory, which causes that already unsteady air to be even more so. This time, however, I got lucky; the air wasn't much worse than normal, so I gave it a try. What you see below is image (processed, in PIPP and Registax 6 if any astronomers are reading), and the same image which has been annotated to show some interesting areas. Information presented was from Virtual Moon Atlas, which I highly recommend.

The numbers are a few of the more interesting areas and are as follows:

1. Mare Humboldtianum. Situated in the zone of librations. (The oversimplified explanation of librations is that the moon, while presenting the same “face” to us all the time, will “rock”, back and forth a little from time to time. When the moon rocks one way (like a rocking chair type rock), we can see a little more of whats on one of the edges. That extra area we can see is the zone of librations. In this case, the moon has rocked a little westerly, so more of the eastern edge is visible than “normal”. ) The sea (Mare) is about 97 miles by 97 miles in area. It is named after Alexander von Humboldt, a 19^th century German naturalist and explorer.
2. Crater Atlas. It's about 53 miles in diameter and about 9100 feet deep. Yes, it's that Atlas, with the weight of the world on his shoulders.
3. Crater Hercules. About 42 miles in diameter and 9700 feet deep. The smaller crater inside Hercules is called Hercules G, the smaller still crater on the southern (actually south west ) rim is Hercules E. “G” is about 8 miles in diameter and about 4100 feet deep, while “E” is about 5 miles in diameter. I don't have a depth (or actually height of the walls) for “E”.
4. This is a “twofer”. The crater is in the middle of a lake. The crater is Burg, which is about 24 miles in diameter and about 6700 feet deep. The lake is Lacus Mortis, the Sea of Death (sounds like a good entry for October 31^st). It's about 91 miles by 91 miles. It's also too deep in shadow to see much else.
5. This crater was so prominent I thought you might just want to know about it. It's called Endymion and it's about 76 miles in diameter, about 13900 feet deep. Apparently, Endymion was a Greek mythological shepherd who bewitched Selene. Who knew?

The last two are hopefully easily recognizable. Saturn I'm sure you will recognize. The lower one is Mars. Both are in the early morning sky, in the constellation of Scorpio.

Failures, Successes, and the Learning Curve

It's been a while since the last post, but I haven't stopped imaging the night sky. As the title suggests, some have been more successful than others, but I have learned some along the way. So, let's start with one of the more successful images, then continue chronologically.

February 27, 2016

NGC2261 HUBBLES VARIABLE

This image, of the cone looking thing, is know as NGC 2261, AKA Hubble's Variable Nebula in the constellation of Monoceros (Unicorn). Don't know where that one is, you say? Well, it's near the brightest star in the sky Sirius... which is also near one of the two most recognizable constellations in the sky, Orion. It's a dim constellation, quite hard to spot, actually. Anyway, the cause of the variability appears to be somewhat uncertain, but possibly caused by dust drifting between the illuminating star (R Mon, which is itself not directly visible) and the nebula. If it is an illuminated nebula, that means it's a reflecting nebula, meaning it's reflecting the light from the star. In other words, it's not glowing (which would be an emission nebula). It's about 2500 ly away and shines about magnitude 9. The variability can be as much a 2 magnitudes.

One thing I didn't know in March, is that I was going down a path of imaging dimmer and dimmer objects, generally speaking, and the problems I was getting myself in for. Hence, the failures and learning curve that eventually follows.

February 29, 2016

M79

I think this one is a successful image as well. It's M79, in the constellation of Lepus (Rabbit), which is just “under” (south) of Orion. It's a globular cluster of stars. The interesting story of M79 is that it is probably an “extra galactic” globular cluster. In other words, it was not formed in our galaxy, the Milk Way. Although there is debate about this, it appears it was formed in the “Canis Major Dwarf Galaxy”, which is currently being absorbed into the Milky Way. (“Resistance is futile”.... sorry Star Trek fans.) Anyway, it's about 41,000 light years away from us and is considered about 11.7 billion years old, which is younger than most of the globular clusters.

Also February 29, 2016

M105

This is where things start to go downhill, as it were. After weeks of working on the situation,I think I have finally figured out a reasonable explanation: the problem is, I think, that the brightness of the objects I'm imaging is so close to the brightness of the sky glow (background light pollution) that normal image processing gets “confused” and adds noise back into the image, making it almost impossible to extract the image of the object I wanted to begin with. It's rather like taking a picture of a polar bear in a snow storm and then trying to get a clear image of the bear. M105 doesn't look like the “typical” image of a galaxy. That's because it's an elliptical galaxy. There are lots of these in the sky. M105 has a brightness of magnitude 10.2, and a surface brightness of 11.3. In the case of magnitudes, the higher the number, the dimmer the object. It turns out that, with the skies I have at the Starlight Observatory, a surface brightness of 11.3 is getting mighty close to the limit of my equipment. That's my excuse, anyway. So, what's the other fuzzy stuff in this image. There is something that looks rather like the galaxy to the upper left of M105. It turns out that this is a galaxy (NGC3384) that happens to contain the quasar 1045+128. NGC3384 is just a little further from us that M105, 38 million ly for 3384 vs. 32 million ly for M105. The third, dimmer, galaxy, to the lower left of M105 is NGC3389. While M105 and NGC3384 are part of the “local” Leo I group, NGC3384 is not. It's about twice as far away.

March 4, 2016

M96

This is one I consider mostly successful. This is M96, a galaxy that's about the same distance from us as M105 and about the same brightness. As you can see, it has a little more of a spiral structure. It's located a little south of M105 in the sky. Whereas M105 is part of the Leo I group, M96 is part of another group called, not to anyone's surprise, the M96 group of galaxies.

March 7, 2016

M109

This is one more on the failure side. The noise (graininess) is apparent and impossible to remove. This galaxy is only a little dimmer than the ones above. Perhaps there was some high cloudiness that I couldn't see? I don't know. I may try this one again at a later time just to see if I can improve on this one. At any rate, this is M109, found around the bowl of the Big Dipper. M109 is a barred spiral galaxy that's about 60 million light years away. By “barred”, that means there is a ”bar” of stars that causes the galaxy to look somewhat like the Greek letter theta ,θ. There are also two more galaxies in this image, but they are difficult to see. They are UGC (for Uppsala General Catalogue of Galaxies) 6940, which is a tiny fuzzy spot just south of M109, and UGC6969 to the left of M109. For a little more information on UGC, see

http://heasarc.gsfc.nasa.gov/W3Browse/galaxy-catalog/ugc.html

April 3, 2016

M41

M41 is a large open cluster in Canis Major. The cluster is just south (below) the star Sirius. It's bright at magnitude 4.5, and is about 2300 ly away. I covers an area of about the same size as the full moon, about ½ degree. I consider this one a success as well.

April 3, 4, 5, 2016

Finally, the challenge that caused me to decide I didn't have enough “signal”. That means that the object was just too close to the sky glow. After working for days trying different processing ideas, I finally decided to look at the underlying raw images. What I found was that the object was only just barely perceptible. The data couldn't be stretched enough to bring the object forward from the background. It would be pointless to show a raw image, but I can and will show what the image looks like when it's just too dim to be separated from the background. It looks like this.

M100 Noise apparent especially in corners (vignetting)

The image is of M100, a galaxy in Coma Berenices, which is just east (left) of the constellation of Leo the Lion. It's about as bright as some of the other galaxies shown above, but the difference is I used 1 minute exposures (a total of 40 minutes worth) vs. 3 minute exposures for most of the other galaxies. Looks really bad. However, one night I shot 13 3 minute shots. It's the luminescence channel only, but you can see the obvious difference. You can even see 5 more galaxies in this image.

M100 3 minutes exposures, in black and white

IMAGE OF 3 MIN 100

Well, kids, that's it for now. I need to try some scope modifications to help with the auto guiding, but hopefully I'll get more images soon. A lot depends on the weather, which has been really bad (for astronomy) for the last year.