Many years ago I came across a reading in Ezekiel that really struck me. The imagery was powerful and disturbing. I recently came across it again in a daily Mass reading in Magnificat. It is Ezekiel 37:1-14.

The hand of the LORD came upon me, and he led me out in the spirit of the LORD and set me in the center of the plain, which was now filled with bones.
He made me walk among them in every direction so that I saw how many they were on the surface of the plain. How dry they were!
He asked me: Son of man, can these bones come to life? “Lord GOD,” I answered, “you alone know that.”
Then he said to me: Prophesy over these bones, and say to them: Dry bones, hear the word of the LORD!
Thus says the Lord GOD to these bones: See! I will bring spirit into you, that you may come to life.
I will put sinews upon you, make flesh grow over you, cover you with skin, and put spirit in you so that you may come to life and know that I am the LORD.
I prophesied as I had been told, and even as I was prophesying I heard a noise; it was a rattling as the bones came together, bone joining bone.
I saw the sinews and the flesh come upon them, and the skin cover them, but there was no spirit in them.
Then he said to me: Prophesy to the spirit, prophesy, son of man, and say to the spirit: Thus says the Lord GOD: From the four winds come, O spirit, and breathe into these slain that they may come to life.
I prophesied as he told me, and the spirit came into them; they came alive and stood upright, a vast army.
Then he said to me: Son of man, these bones are the whole house of Israel. They have been saying, “Our bones are dried up, our hope is lost, and we are cut off.”
Therefore, prophesy and say to them: Thus says the Lord GOD: O my people, I will open your graves and have you rise from them, and bring you back to the land of Israel.
Then you shall know that I am the LORD, when I open your graves and have you rise from them, O my people!
I will put my spirit in you that you may live, and I will settle you upon your land; thus you shall know that I am the LORD. I have promised, and I will do it, says the LORD.

This time, I was more struck by the image of dry bones coming to life. A real feeling of resurrection and rebirth. This is certainly a powerful reading.

A couple of weeks back, during the last quarter Moon, I was able to get some decent data of M101, the Pinwheel Galaxy. M101 is a spiral galaxy in Ursa Major and is 27 million light years away.

The image is from 160 minutes of LRGB data. That’s 90 minutes of luminance, and 23.3 minutes each of red, green and blue, binned 2×2. LRGB imaging takes advantage of the fact that we perceive most of the detail in an image from the black and white, or luminance part of the image and less detail from the color. I obtained 90 minutes of high-resolution black and white data and combined it with lower resolution color data to produce the image. The color was obtained by binning the pixels, or adding four pixels to create one. This allows for more data collected in a shorter period of time but at half the resolution.

Here is the result. Click on the picture to go to the gallery where you can see a full-sized version of the image.

160 Minutes LRGB (90:20:20:20 subs 300:200:200:200×18:7:7:7)

It has been three months since clear skies, the new Moon, and being in Lake Riverside have converged on the same day and allowed for imaging. These factors came together on May 15th. I collimated the C-11 back at the full Moon and was ready to go. (Dew foiled my attempt to get even any Ha data that full Moon night but that is another story.)

I used my general approach for finding targets. I use The Sky’s database manager data wizard to query objects above 40 degrees or so. Moving from object to object I record my interest, the transit time, and the availability of a guide star. Up until this weekend I have tried to capture all of my data on one side of the meridian, preferably the east. This simplifies the taking of flats (with the ST-10 the camera rotates 180 degrees to maintain framing after a meridian flip) and the east has a better view from the western pier in the observatory.

I chose to image NGC 5033, a spiral galaxy in the constellation Canes Venatici. Is looks very interesting and has a very bright star that can be used for a guide star. Astronomical twilight would occur at about 9:15 PM PDT and the galaxy would transit at 10:32 PM. I hoped to get data both before and after transit, that being the best time to image as the object is highest in the sky.

I had my usual troubles with autoguiding and initial start-up but got imaging going by 9:40 or so. In the first of many little glitches, I had set CCDCommander to send me a text message when the first set of luminance images were done, but the message didn’t get sent because Zone Alarm had interrupted the request to send e-mail. Security software can be annoying. I was in the house watching Midway with the family, so I didn’t go back to get the next series started and lost 20 minutes of imaging time before the meridian crossing.

I planned on getting 50 minutes of luminance data and 20 minutes each of red, green, and blue. After having trouble on my last imaging outing with dark pixels on the color images, I wanted to make sure I had at least six sub-exposures and adequately dithered the frames—six frames to enable a sigma reject algorithm and dithering to move the dark pixels. So my luminance exposures were 300 seconds and my color were 200 seconds. I had other little issues with losing sync on the meridian flip and FocusMax acquire star not returning exactly to the original framing but overall things went fine the rest of the night. These problems would be solved if I were able to spend several days in a row in the observatory—a good goal for the future. I was able to use the new window shade to take flats after putting the white lights on the dimmer for the rope lights.

I ended up with 110 minutes of LRGB data, 50 minutes of luminance and 20 each of red, green, and blue. The RGB images were binned 2×2. I performed my data reduction, alignment, and combination in CCDStack. To simplify alignment, I process the luminance first, then save a binned copy of the final image. I then use that binned image as the master to align each of the sets of color images. This means that frames are only re-sampled once for alignment and that all combined frames are fully aligned.

Once I was processing the data it was clear that I really had inadequate imaging time for this object. At magnitude 10, it is quite dim. When the image was processed to bring detail to visibility, it was quite noisy and grainy. So I did the best that I could with it.

I did most of the processing in PixInsight. I have a standard approach when starting on an image that makes the later combine steps easier. The basic idea is to get a standard crop of the images that will work across all frames, eliminating any artifacts around the edges from the combine / integration process. The RGB frames are scaled up two times to match the luminance. Then, using the dynamic crop tool, I select a crop that will include solid data from all frames. I save an instance of the crop settings on the desktop and then save the process icons. This allows me to start and re-start work on each frame from a consistent point.

On the luminance, I used both the histogram tool and curves to bring out the details. A very nice feature of the histogram tool in PixInsight is the ability to see the number of pixels you have clipped so there is no guesswork. Generally I take several quick passes through the data before settling on a final processing approach. On this image, I took a copy of the luminance and applied a four-level HDR wavelet transform, recombining it with the original using PixelMath. This brought out the dust lanes in the center of the galaxy. I did need to create a star mask to preventing ringing when doing the HDR wavelet transform.

I tried to keep things simple on the color data. I used a channel combine to create an single RGB image, then used histogram to eyeball the black points across the colors. There is are some new tools in PixInsight that really helped the color. The first is Background Neutralization. In my experimentation with this tool, it will allow you to drop out the noisy background in a color image. I used the tool in truncate mode to eliminate most of the background data in the RGB frames. This is consistent with what RickJ suggested in the BAUT Astrophotography Forum. There is also a color calibration tool that appears to correct your color balance. I’ll have to work on understanding that.

My processing approach on images is to create solid luminance and RGB images. I then use channel extraction to pull the individual red, green, and blue components out of the RGB image. The final combine step is to use LRGB
Combination to create the final LRGB image. I touched up color and contrast and then moved to Photoshop.

In Photoshop, I used clone stamp and healing brush to fix a couple egregious color issues. I also used Noel Carboni’s Astronomy Tools actions to reduce noise in the image and tweak the star size. The final step was to add a layer processed with a high pass filter, masked to reveal only a few key locations, and merged with “soft light” blending mode to highlight some details.

Here is the final image. Still a bit noisy and needing more data, but I think it looks OK. Click on the image to go to the gallery and a full sized image. Comments and suggestions are always welcome.

We hosted a Cub Scout troop tonight at our house and the observatory (in Los Angeles). Some friends of ours son is a member of the troop and they asked us to help with a night of astronomy focused on getting the troop members their Astronomy Belt Loop.

It was great fun and I think a great success. We had 6 Scouts, parents, and a sister as our guests. After they completed their opening ceremonies, my wife went through the specific learning about astronomy that is required for the belt loop (what is a planet, etc.). Once it was dark — well, time for a digression. It is dark a bit late this time of year because of the early start of daylight savings. It is starting too early. End of digression.

I had opened the observatory at the start of the meeting. Good hoots and hollers from the scouts at the opening. Once it was dark and the lessons were complete, we started observing.

Mars was first and was not too exciting. In the 8″ SCT and a 9mm Nagler (225X magnification), it was just a small disk with almost no features. We were pushing the seeing in any case.

The next target was M42, the Nebula in Orion. The Trapezium was a clear four stars and there was a nice haze of nebulosity around it. This got a few aahs from the Scouts and other guests.

We then moved on to the Moon. This turned out to be the hit of the night. In the 35mm plossl, it was a full disk view with the terminator right in the middle of the Moon. Great detail in the maria and the peaks. Lots of oohs and aahs. I then went back to the 9mm Nagler for a closer look and this brought some serious study by one of the Scouts. Aimed at the north pole of the Moon, we had a view that showed the shape of the Moon with lots of crater detail. A big hit.

We had reached 8:40 pm or so, so the troop left except for our friends and their son. We chatted a bit and were looking at the constellations (we could pick out Orion, Gemini, Leo, Canus Major [Sirius anyway], and the Big Dipper). Then I saw a bright object at about 25 degrees and realized we had a jackpot view — Saturn!

Saturn was low but we could see the rings well and two moons clearly, Rhea and Titan. Saturn is always a big hit. So we finished the night on a high note.

It was really nice to be able to share both the knowledge of Astronomy and the experience of looking through the telescope with a bright and eager group of kids. Well behaved too. They were all very thankful. And I am very thankful that I had the ability to share the view of the sky with them.