The Cat's Eye Nebula

Yesterday I promised that I would upload my latest image, the Cat's Eye nebula, and so here it is (with the off-color NB stars - I'll reprocess with RGB stars later when I acquire them).

NGC 6543 - the Cat's Eye Planetary Nebula
EdgeHD11/ASI2600mm - 42x600sec Ha; 43x600sec O3
14 hours integration time May 31, June 2 and June 5, 2023 

This is the famous Cat's Eye nebula, a remarkable planetary nebula (PN) located in the constellation of Draco the dragon. It was discovered by William Herschel on February 15, 1786. It resides at an  estimated distance of 3,262 light years from earth. The inner core is about 16 arc sec in diameter, which at it's current distance would make it about 0.25LY wide. Images from the Hubble telescope made this object a subject of popular review when they showed the central core of the nebula in exquisite detail, revealing knots, jets, bubbles and complex arcs, all being illuminated by the central hot planetary nebula nucleus. My image shows the surrounding outer halo (about 4.7LY in diameter) in the HOO NB color palette. Both the central WR:+O7 spectral class PNN star and the concentric rings surrounding the inner core can be plainly seen. Based on both the estimated distance and the expansion rate the age of this PN is about 800-1200 years old.

The image was composed of 42 Ha subs and 43 O3 subs, each 600 seconds of exposure. Since the nucleus of the nebula is so very bright (shining at magnitude 8) the 600 seconds really washed out the core and so I had to carefully process the image with a High Definition layer routine to bring out some of the internal detail and reduce the overall intensity.  There is evidence of some processing artifacts present, but adding more data later will probably resolve that issue.  I had also planned to capture RGB stars to replace the NB stars, but between the full moon and the smoke drifting into Maryland from the Canadian fires I had to forgo those and settle on the NB stars. I hope to replace them with RGB stars when I capture more data of this wonderful object.

Smoke in Maryland - And a Feature Article on Your's Truly

Here it is - Monday evening; clear sky, cool temps, low humidity. What more can you ask for? Should be a great night to capture the RGB stars I need for my latest project. But, where are the stars? And what's with Venus, so pink and dim, when it should be brilliant white. Why smoke, of course! Yep, the Canadian fires are filling our skies with a fairly thick haze of smoke. So no imaging tonight. I'll probably process the subs I got of the Cat's Eye nebula without the colored stars. Maybe I'll capture them later and add them in at a later date. I'll post the image later this week.

On another note ... back in March, Photonic Cleaning Technologies, a company that developed a polymer cleaning solution used by professional observatories and industrial optical organizations, contacted me after I had a conversation with one of the owner/engineers about using their First Contact Polymer to clean my telescope optics. We had a great talk about astronomy and astrophotography, and it was soon after that conversation that Debra Giesen emailed me about publishing an article about my hobby on their website. Of course I jumped on the opportunity and started writing the first draft. All I needed to do is agree to include a short  testimony on how I liked the Polymer cleaner. Not only would the article be posted on their website, but would be a feature article in the June edition of Amateur Astrophotography Magazine.

Well, things didn't go all that well. The owner/creator/manager of Amateur Astrophotography Magazine is temporarily suspending future publishing until early next year as he deals with some medical issues. He is confident that the magazine will be back in operation in early 2024 and I will be first on the publication list. But the article, "Astrophotography from Light Polluted Reisterstown" is posted on the Photonic Cleaning Technologies website. Check it out.

Supernova 2023ixf in M101

I'm sure many of you may already know of the supernova that occurred in the Pinwheel galaxy, M101. I wanted to capture it as soon as I could but, as usual, clouds prevented me from doing so until May 26, when it cleared sufficiently to get a decent image.

I had taken an image of M101 way back on Dec 28, 2013, when I was just starting out with astrophotography. I had recently acquired my large telescope (the EdgeHD11) and this was one of my first attempts at imaging a galaxy. I didn't even own a dedicated astro camera back then - the image was taken with my Canon 50D body. I'm not sure why I haven't taken a recent image of M101 as it is a wonderful galaxy, but that's another story.

Amateur astronomer Koichi Itagaki discovered it on May 19, 2023. The supernova should remain visible to amateur astronomers with backyard telescopes for a few months. The supernova – named 2023ixf – lies in the direction of the constellation Ursa Major, near the end of the handle of the Big Dipper.

So here is my image of M101 with the supernova marked (and the 2013 image for reference).

Supernova 2023ixf in M101
May 26, 2023 - EdgeHD11/ASI533mc
40x180sec with UV/IR block filter

M101 - Dec 28, 2013
EdgeHD11/Canon 50D
12x120sec ISO 3200

You can read more about this object at SkyAndTelescope.  Details of my image can be found at Astrobin.

Latest image from Mikey's Place - the Sombrero Galaxy

Since galaxy season is upon us I decided to give the ASI533mc a workout. For those of you who do not know what galaxy season is here is a short explanation.

There is a region in the sky where a significant number (the vast majority actually) of galaxies congregate. As the Earth swings around its orbit in the spring, it faces the plane of the our own Milky Way but at night it faces a part of the sky that reveals what some of us call the Realm of the Galaxies. During the months of April, May and June, several hundred of these galaxies become easy to image with telescopes of 10 inches aperture or more. And, with just a little extra effort, up to thousands can be imaged but will appear rather small as they are much farther distant.

Most of these galaxies are clustered around the constellation Leo the Lion and just beyond Leo's tail. This cluster, some 4,500 or more of them, is known as the Coma-Virgo Cluster and lies about 60 million light years away. This enormous distance is why these galaxies are so faint. Some of these galaxies are larger and brighter than our Milky Way galaxy but still hard to see. 

Sombrero Galaxy - May 11, 2023
EdgeHD11 Telescope / ASI533mc camera
58x120sec subs thru UV/IR cut filter

The photo displayed here is the Sombrero Galaxy (one of the Messier objects, M104, and also designated as NGC 4594). It lies 31.1 million light years from the Milky Way and is slightly larger in size at about 94,900 light years in diameter (the Milky Way is estimated to have a diameter of 87,400 light years). Because of it's large distance from us it appears in the sky to be only 9' x4' (the ' is a minute of arc which is 1/60 of a degree, making the size about 0.15 degree in the long dimension). It has a very bright nucleus, and a rather large central bulge (which is unusual for galaxies). In addition it sports a prominent dust lane in its outer disk, which is viewed almost edge-on. It is the dark dust lane and the bulge that give it the appearance of a sombrero hat (thus the name).

More details about my image of the Sombrero can be found on AstroBin.

Update on the Medusa Nebula

 A few days ago I posted my image of the Medusa nebula. I had mentioned that there were some problems with the level of Sii data and that the blue star subs were really bad.

It turns out there were other issues as well - having to do with the settings used to calibrate and stack the narrowband subs. I sent my raw data files to a fellow astrophotographer out on Astrobin, Uwe Deutermann, and he was able to process them with no such issues and create a much better final image. Here is that result as a collaboration effort of the two of us: my data, Uwe's processing.

Medusa Nebula -- Abell 21, Sh2-274

Later on another astrophotographer on Astrobin, George Yendrey, provided a very complete evaluation of my issue with the processing and uncovered an incorrect setting/parameter I was using in calibrating the subs. Once I set the parameter correctly I was able to reprocess my data and get similar results to what Uwe had provided. Such is the huge benefit of having an online collaboration site like Astrobin where fellow astrophotographers can ask questions, and exchange knowledge.

The complete dialog of the journey to get this image can be found on Astrobin.

The Medusa nebula

Got some clear nights as of late so I immediately got the scope out under the stars to do some imaging.

Seems like everyone as of late is posting the Medusa nebula on Astrobin.  Mine is no where as good as any of them, but it is the object I used to check on my recently returned EdgeHD11 from Celestron (had it in for cleaning and maintenance) and my new Optolong filters and 2" FW. 

The Medusa Nebula is a planetary nebula in the constellation of Gemini. It is also known as Abell 21 and Sharpless 2-274. It was originally discovered in 1955 by University of California, Los Angeles astronomer George O. Abell, who classified it as an old planetary nebula. It is 1,500 light years distant spanning about 4 light years across.

I had lots of problems getting this object imaged. One is the lack of sufficient data in S2. The other was the fact that the focus on the Blue filter was off and so I got some wonky stars. Oh well, enough of the sad commentary, here it is.

The Medusa nebula - SHO w/RGB stars
March 19, 21 and 26, 2023
EdgeHD-11; ASI2600mm  -  9 hours Integration Time

There was another issue I had but that is potentially going to be discussed in a later post. I didn't do any calibration on these subs - no darks, no flats. This was because of something that was occurring in the PixInsight WBPP script that essentially wrecked my Ha stack. The O3 and S2 data were fine. Not sure why this happened, but I am researching it.

More details on this imaging run can be found on my Astrobin site.

Relativity Space launches 3D-printed Terran 1 rocket

I've always wanted to try out the new 3D printers that are all the rage these days, but I would never have guessed that a Space company would, or could, print a working rocket. 

On Wednesday night a Seattle company, Relativity Space, launched the first 3D-printed rocket, named "Terran 1", on a test mission from Cape Canaveral.  The primary aim of the flight was to put a completely new launch vehicle through its paces, and place a small memento plaque into orbit.  

Methane-tinged blue flames - Relativity Space / Michael Baylor © Provided by Geekwire

The takeoff of the two-stage, 110-foot-tall Terran 1, was picture perfect, and unique in that the exhaust was bright blue owing from that fact that it used Methane as a propellent (another experimental design feature).

The rocket successfully reached Max-Q, a point where the stress on the rocket's superstructure is the greatest, thus demonstrating that 3D printed components hold up to the severe stresses of launch and boost against the force of Earth's gravity.

But an anomaly in the second stage engine prevented stage two's ignition and thus made orbital insertion impossible. Nonetheless, the rocket demonstrated a first for space vehicles and future attempts to reach orbit are just around the corner as the company plans additional flights and larger vehicles.

Full article (and video) at: GeekWire

Experimenting with DuoBand filters

I was experimenting with the ZWO DuoBand filter that came with my ASI533mc using M42 as the subject.  This photo is a combination of images: DuoBand (180sec) + RGB (120sec) + RGB (30sec) Stars.  I processed the DuoBand subs separate from the RGB, producing two master images; one DuoBand the other RGB.  I extracted the R, G, and B from the DuoBand before applying the NBRGBCombination process in PixInsight.  I then used Bill Blanshan's technique for adding in the RGB stars (using the 30sec master). 

The core is a bit blown out, but the overall result is not all that bad. I'll need to try some other objects using this imaging combination and processing technique.

Comet C/2022 E3 leaving the solar system

Clouds, clouds, clouds, and then more clouds. But on February 8th when it looked like another cloudy night, there was a break between a cloud deck to the west and a cold front that just passed to the east giving me about 6 hours of mostly clear skies. Since I was hoping to get some more images of this comet before it left for good (well, at least for another 50,000 years) I had to set up quickly and take the opportunity presented to me.

The optics were still not up to par - the stars at the edges and corners of the field were still showing some severe signs of coma and out of focus (as I mentioned in my previous post on January 31). This made the postprocessing a bit difficult, and I had to pull out a few tricks to get the subs to stack properly. 

Comet C/2022 E3 (ZTF) - February 8, 2023
William Optics ZenithStar 61;  ZWO ASI2600mm
2h57m total integration time

As anticipated, the comet had dimmed quite a bit and I was not able to get the ion tail to show clearly (may be due to some of the thin clouds that were still present and the fact that the moon was nearly full). If I stretch the image a bit more you can just make out the tail, but the quality of the overall image degrades a lot. So I decided to leave well enough alone.

Still waiting for that next best naked-eye comet to arrive. But this one was fun to follow and image.

Comet C/2022 E3 seems to be dimming

Skies cleared just enough this evening to set up my equipment and capture some more subs of comet C/2022 E3. What seems to be immediately obvious is that the comet is dimming. Although it could be due to thin clouds, or the moon's interference, initial examination of the raw images show a marked decrease in intensity of the coma and the fan-like dust tail. The individual subs show no sign of the ion tail. Some of this is also due to the geometry of comet's orbit as well.

Once I process the images and see what the stacked version looks like I'll post here. Probably will take a day or two before I get the time to do the processing.  

Observing comet C/2022 E3

Today, comet C/2022 E3, a visitor that has not visited the Earth since the last ice age, will make its closest approach to our planet, or perigee.  Then it will speed away and not return for about 50,000 years. 

Although it will be at its brightest during this time, the full moon is joining the show and will make it hard to see without optical aid. But in the days after the full moon (Feb 6-22) the comet will still be very bright and well placed for viewing in the NE sky, almost directly overhead (see diagram below). The comet passes close to the red planet Mars on the 10th-11th, and then passes just to the east of Orion's shield on Feb 16-22.

It's closest point (perigee) is a distance of around 26 million miles from our planet, about 28% of the distance between Earth and the sun. You can also watch the comet live online on Feb. 1 in a free webcast at 11 p.m. EST (0400 GMT) from the Virtual Telescope Project.