Tag Archives: Messier

M33 The Triangulum Galaxy and its H-II Regions

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Messier 33, the Triangulum Galaxy, is a galaxy in the same local group as our own Milky Way.  M33 is located approximately 2.74 million light years away, and it has an apparent visual size of 60.26 by 35.48 arcmin, so it is approximately 48 by 28.3 thousand light years across.  It is classed as a flocculant (fluffy, with less well-defined arms) spiral galaxy – in this image, one set of arms curve up from the right side and a second set of arms curve down from the left side.  

Because, by galaxy standards, M33 is relatively nearby (in the same local group as our own galaxy), we can see a lot of detail in it.  In fact, we can see the same kind of things in it that we see in our own galaxy – Hydrogen II (H-II) star forming region nebulas, supernova remnants, and even planetary nebulas.  

Most obvious in this image and in the black-and-white Hydrogen alpha (H-alpha) image are the enormous, bright, young H-II star forming region nebulas.  These are all clouds of atomic hydrogen ionized and lit up by the young, massive, star clusters that formed within them.

The brightest H-II star forming region in M33 is NGC604 in the innermost arm to the lower left of the main image.  It has an apparent visual size of 2 by 1.2 arcmins, so it is approximately 1600 by 950 light years across.  This region contains 200 massive, young, hot O-type and Wolf-Rayet stars that are about 3 million years old as well as an older population of stars that are 12 million years old.  This region may have hosted a sequence of star forming events, where one set of stars forming triggered the formation of the next set.  

The second brightest H-II star forming region in M33 is NGC595 at the top left of the galaxy core.  It has an apparent visual size of 1 arcmin, so it is approximately 800 light years across.  It contains about 250 type OB stars and 10 Wolf-Rayet stars with an approximate age of 4.5 million years old.

The third brightest H-II star forming region in M33 is NGC588 in the top of the second arm to the right.  It has an apparent visual size of 30 by 50 arcseconds, so it is approximately 400 by 665 light years across.  It contains a young star cluster that is about 3.5 million years old.

I started working on collecting data on M33 at the end of 2024/start of 2025 using my smaller 73 mm “Z” telescope, but I did not end up with sufficient data for a good image.  When I was imaging Comet Lemon with “Z” last fall, I collected more data while I was using that telescope and finally collected enough.

I combined several paths of processing to make this image.  I used only the 30 second Red Green Blue (RGB) data (about 26 minutes per color) to generate the RGB stars.  I used all the RGB data (4.5 hours of red data and 2.6 hours each of green and blue data) to generate an RGB image of the galaxy.  I processed the Hydrogen alpha (H-alpha) data (8.3 hours of data) by continuum subtracting a starless red from the starless H-alpha, then processing and stretching the resulting image.  I processed the Oxygen iii (Oiii) data (6.6 hours of data) by continuum subtracting a starless blue from the starless Oiii data and then processing and stretching the resulting image.  The continuum subtraction removes the “starlight” from the broader-band stars from the H-alpha (or Oiii) data to leave just the H-alpha (or Oiii) sources.  I stretched the H-alpha and Oiii separately to retain some detail in the very bright H-alpha emissions from the NGC604 H-II region as well as detail in the RGB galaxy.  Finally, I used NBColourMapper to add the H-alpha as red and the Oxygen iii as turquoise to the RGB galaxy.  

It is amazing to me that we can see star forming regions in other galaxies.  Our universe is still under construction!

Camera geek info:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila SHO and RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • William Optics Uniguide 32MM F/3.75
  • ZWO ASI220MM-mini
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • November 23, 2024
    • 229 60 second Gain 150 Ha lights
    • 30 1.0 second Gain 150 Ha flats
  • December 19, 2024
    • 99 60 second Gain 150 Oiii lights
    • 30 0.5 second Gain 150 Oiii flats
  • December 20, 2024
    • 28 60 second Gain 150 Ha lights
    • 30 1.0 second Gain 150 Ha flats
  • December 31, 2024
    • 185 30 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
  • January 1, 2025
    • 46 30 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
  • January 23, 2025
    • 24 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • October 9, 2025
    • 68 60 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
    • 71 60 second Gain 150 Green lights
    • 30 0.02 second Gain 150 Green flats
    • 69 60 second Gain 150 Blue lights
    • 30 0.02 second Gain 150 Blue flats
  • October 10, 2025
    • 61 60 second Gain 150 Red lights
    • 53 30 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
    • 64 60 second Gain 150 Green lights
    • 52 30 second Gain 150 Green lights
    • 30 0.02 second Gain 150 Green flats
    • 64 60 second Gain 150 Blue lights
    • 52 3 second Gain 150 Blue lights
    • 30 0.02 second Gain 150 Blue flats
  • October 12, 2025
    • 49 180 second Gain 150 Oiii lights
    • 30 0.5 second Gain 150 Oiii flats
  • October 18, 2025
    • 50 180 second Gain 150 Oiii lights
    • 30 0.5 second Gain 150 Oiii flats
    • 73 60 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • 30 Flat Darks from library matching flat lengths
  • 30 Darks from library

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • NBColourMapper
  • Generalized Hyperbolic Stretch

Sagittarius, the Teapot, Pours out the Milky Way, Messier Objects, and Comet C/2025 R2 SWAN

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By Friday October 17, 2025, Comet C/2025 A6 Lemmon had become an evening object, so my husband and I drove to Sargent, Texas for darker skies (Bortle 4).  Unfortunately, the clouds stayed near the horizon and hid Comet Lemmon.  It was quite windy out, so I didn’t want to get out my telescope.  

However, there was another bright comet in the sky, C/2025 R2 SWAN, and I also had my camera to try to capture a wide field image, so I set the camera up to capture a wide field with Comet C/2025 R2 Swan.  I didn’t have much time to capture it before it was obscured by clouds and only got 7 minutes of data.  

The comet was above the constellation Sagittarius which is in the direction of the center of the Milky Way, so it is a particularly bright section of the Milky Way and contains multiple Messier Objects, marked in magenta.  Messier Objects are Deep Space Objects that comet hunter Charles Messier put on a list of “not-comets.”  There are 17 Messier Objects in this image, four of which I have imaged before in more detail.  It’s fun to compare them to an actual comet here.  While the comet stands out with its greenness in the image, visually it would be a fuzzy spot like the others … except that it very slowly moves across the field of view.

Apparently I forgot to take flat frames for this image, so I used a synthetic flat.

Camera geek info – camera:

  • Canon EOS 60D in manual mode set at f/2.8, 10 second exposure, ISO 4000
  • Sigma 24-70 mm f/2.8EX lens, set at 24 mm, manual focus
  • Tripod
  • Intervalometer 

Frames – camera:

  • October 17, 2025
    • 42 10 second lights
    • Matching darks from library

M16 The Jewel Box of Creation (or the Eagle Nebula)

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The traditional name for Messier 16 (M16) is the Eagle Nebula or the Star Queen Nebula.  However, when I saw the first Hydrogen alpha narrowband images that went into this image, I did not think it looked like a bird. I thought the round nebula on the top looked like the knob on top of the cover of a jewel box (or perfume bottle).  The bright inner center of the nebula with its young stars looked like jewels (so I picked the jewel box analogy).  And the pillars in this nebula are the famous Pillars of Creation imaged by the Hubble Space Telescope.  So I think the name the “Jewel Box of Creation” is also a lovely description of this beautiful Deep Space Object (DSO).  What do you think it looks like?

M16 contains two related things: an emission nebula numbered IC4703 or Sharpless Sh2-49 and an open cluster numbered New General Catalogue (NGC) 6611.  The emission nebula is part of Giant Molecular Cloud W37, an interstellar cloud of gas molecules, primarily molecular hydrogen (H2) and carbon monoxide (CO), the mass of which is calculated to be 170,000 times the mass of the Sun.  The nebula is a large star-forming region ionized by the stars it generated.  The open cluster of stars has an inferred population of 8100 stars including at least 137 visible young stars in the Gaia Early Data Release 3 (EDR3) with good data and magnitudes greater than G=17.5 in two populations: one older (7.5 +/- 0.4 million years old) and more spread out and one younger (1.3 +/- 0.2 million years old) and more concentrated.  (As a point of reference, our own star, the Sun, is 4.6 billion years old – 3500 times older than the younger stars!  What are you 3500 times older than?). The young population includes 19 type O stars which are high mass, hot, blue stars with short lives due to their high mass.  One binary pair of these type O stars, HD168076, is the brightest star in the cluster visually, has a mass of 75 to 80 times the mass of the Sun, and is the primary source ionizing the nebula.  

M16 is located in the Milky Way, approximately 5513 light years away, and it has an apparent size of 1.3 degrees, so it is approximately 125 light years across.    

In this image, the stars came from images using red-green-blue filters with about 30 minutes of data each, and the nebula came from images using Sulfur ii (4.15 hours of data mapped to red), Hydrogen alpha (1.75 hours of data mapped to green) and Oxygen iii (2.25 hours of data mapped to blue) filters, the standard SHO mapping.  But after doing that mapping, I used Narrowband Normalization to shift the colors so that it wasn’t overly green and to enhance the reds and blues.  This tool made getting the colors in this nebula look right a lot easier!  Even so, I ended up making multiple attempts to try to show it well and got some excellent advice on astrobin on how to improve the image. The nebula was processed separately from the stars to maximally enhance it.

I think this nebula and star cluster are absolutely gorgeous!  We live in a universe filled with wonders.

Camera geek info – Narrowband:

  • William Optics Pleiades 111 telescope
  • ZWO 2” Electronic Filter Wheel
  • Antila SHO and RGB filters
  • Blue Fireball 360° Camera Angle Adjuster/Rotator
  • ZWO ASI183MM-Pro-Mono camera
  • William Optics Uniguide 32MM F/3.75
  • ZWO ASI220MM-mini
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • August 28, 2025
    • 96 20 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 91 20 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 92 20 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
    • 24 180 second Gain 150 Sii lights
    • 30 0.5 second Gain 150 Sii flats
  • September 9, 2025
    • 35 180 second Gain 150 Ha lights
    • 30 0.5 second Gain 150 Ha flats
  • September 11, 2025
    • 45 180 second Gain 150 Oiii lights
    • 30 0.2 second Gain 150 Oiii flats
  • September 12, 2025
    • 59 60 second Gain 150 Sii lights
    • 30 0.5 second Gain 150 Sii flats
  • 30 Flat Darks matching flat durations from library
  • 30 Darks matching light durations from library

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Narrowband Normalization

William Optics Pleiades 111 First Light and More Nights with M101 the Pinwheel Galaxy

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I chose M101 as my “first light” object for my new William Optics Pleiades 111 telescope, “Blue,” because it was galaxy season when I started imaging back in May and I had imaged it before so I could compare the results with my smaller telescope setup.

My oldest comparison image is from June 2023, when there was a supernova in the galaxy.  I collected the data from the fabulous dark skies in Dell City, Texas, using my William Optics Zenith Star 73 III APO telescope and a Canon 60D camera.  The image was made from 10.6 hours of data.

My next comparison image is from January 2024.  I collected the data from Friendswood, Texas with suburban light pollution using my William Optics Zenith Star 73 III APO telescope and my at-the-time new ZWO ASI183MM-Pro-Mono camera and ZWO filter wheel. The image was made using 59 minutes of red data, 60 minutes of green data, and 57 minutes of blue data. 

My next image is from May 2025 in Friendswood, Texas, and it was the first light on my William Optics Pleiades 111 telescope “Blue” using a new guide camera and using my existing ZWO ASI183MM-Pro-Mono camera.   The image used only 52 minutes of red data, 66 minutes of green data, and 86 seconds of blue data, and I had to adjust some of the local normalization parameters to accept lower quality data to get it to process.  I had been excited to have a semi-clear night, so I had gotten the telescope out even though seeing wasn’t great.

My final (for now) image is from May – August 2025 in Friendswood, Texas.  The new telescope cloud curse has been particularly strong with this telescope, and when there weren’t clouds, there was dust or a full Moon. Nevertheless, I persevered over 8 nights to produce the final image, ending up using 5.9 hours of red data, 5.3 hours of green data, and 4.8 hours of blue data.

There was a huge improvement in the detail (most obvious with the stars) when I switched to the astrocamera, and another huge improvement in the detail (most obvious in the galaxy and in the background galaxies) when I switched to the larger telescope and guiding capability.

My main subject, M101, the Pinwheel Galaxy, is an intermediate spiral galaxy, between a barred and an unbarred spiral galaxy.  It’s located approximately 23.2 million light years away, and it has an apparent size of 24 arcminutes, making it about 162 thousand light years across. 

Also obvious during imaging was NGC5474, which is a peculiar dwarf galaxy that is a companion to M101.  Its interaction with M101 has distorted it.  It also appears to have a spiral structure, making it a dwarf spiral galaxy.  It’s located approximately 22.4 million light years away, and it has an apparent size of 4.68 arcminutes, making it about 30.4 thousand light years across.

What surprised me with in the final image was the sheer number of tiny galaxies in the background.  In addition to NGC5474, there was NGC5477, a dwarf galaxy which is 22.05 million light years away, with an apparent size of 1.7 arcminutes, making it 10.9 thousand light years across.  PixInsight also labeled 8 other galaxies in the Principal Galaxies Catalog (PGC).  And when I looked in detail at the image, there are a ton more tiny distant galaxies in the background.  WOW. 

Now M101 is really too low in the sky to get any good data from my driveway, so I am moving on to other subjects.  I look forward to coming back to this one in the future and capturing more of the amazing background galaxies. 

Our universe is packed with cool stuff!  

Camera geek info for final image:

  • William Optics Pleiades 111 telescope
  • ZWO 2” Electronic Filter Wheel
  • Antila RGB filters
  • Blue Fireball 360° Camera Angle Adjuster/Rotator
  • ZWO ASI183MM-Pro-Mono camera
  • William Optics Uniguide 32MM F/3.75
  • ZWO ASI220MM-mini
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames for final image:

  • May 9, 2025
    • 13 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
  • May 23, 2025
    • 29 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
  • May 24, 2025
    • 2 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 54 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 50 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • June 6, 2025
    • 84 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 72 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 63 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • June 7, 2025
    • 100 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 74 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 63 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • July 10, 2025
    • 57 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 46 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
  • July 11, 2025
    • 69 60 second Gain 150 Red lights
    • 30 0.02 second Gain 150 Red flats
    • 23 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 12 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • July 22, 2025
    • 93 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • August 1, 2025
    • 51 60 second Gain 150 Green lights
    • 30 0.01 second Gain 150 Green flats
    • 6 60 second Gain 150 Blue lights
    • 30 0.01 second Gain 150 Blue flats
  • Darks, Flat darks from library

M101: First Light with William Optics Pleiades 111 Telescope “Blue”

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It’s a well-known astrophotography curse that buying new equipment means weeks, if not months, worth of cloudy skies.  My new telescope, a William Optics Pleiades 111, a 11.1 cm/4.37 inch diameter refractor that I’ve nicknamed “Blue”, was no exception.  It took about a month after I got the telescope (and the additional two counter weights I needed to balance it) for the skies to at least somewhat clear.  I got everything set up, just to watch the clouds roll in.  Happily, they then rolled back out.  And then rolled back in.  And out.

I ended up with enough data to make a first light picture, but I’ll need to collect more data for a final image.

I had contemplated what to image for first light.  Since the telescope name is Pleiades, the Pleiades would have been a good target, except they’re currently barely above the horizon at sunset.  My favorite nebula, the Orion nebula, would have been a good target, except it’s also currently barely above the horizon at sunset.  It’s “galaxy season,” so I decided to image a galaxy.  I’ve imaged M101 before because it hosted a supernova in 2023, so it gave me a good point of comparison.  

The comparison isn’t entirely a fair one.  On the one hand, this is an entirely new setup, with a much larger diameter telescope, an astro camera instead of a consumer camera, and a guide scope and guide camera to better control the tracking mount.  Additionally, I’ve picked up a lot of processing skill in the last two years, such as using shorter images for the stars so they don’t “bloat.”  On the other hand, this was 3.4 hours of galaxy data from my Bortle 7-8 light polluted driveway instead of 10.6 hours from the Bortle 2-3 dark skies of Dell City.

Because of the light pollution and limited imaging time, there is a lot more background noise in the new image.  But the stars are enormously improved from the old image.  And there is more detail in the new image.  I can’t wait to see how an image with more data turns out!

Once the clouds roll away again ….

Camera geek info May 9, 2025 (new image):

  • William Optics Pleiades 111 telescope
  • ZWO 2” Electronic Filter Wheel
  • Antila RGB filters
  • Blue Fireball 360° Camera Angle Adjuster/Rotator
  • ZWO ASI183MM-Pro-Mono camera
  • William Optics Uniguide 32MM F/3.75
  • ZWO ASI220MM-mini
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames (new image):

  • May 9, 2025
    • 32 30 second Gain 150 Red lights for stars
    • 24 30 second Gain 150 Green lights for stars
    • 22 30 second Gain 150 Blue lights for stars
    • 53 60 second Gain 150 Red lights for galaxy
    • 66 60 second Gain 150 Green lights for galaxy
    • 86 60 second Gain 150 Blue lights for galaxy
    • 30 0.2 second Gain 150 Red flats
    • 30 0.1 second Gain 150 Green flats
    • 30 0.1 second Gain 150 Blue flats
  • Darks, Flat darks from library

Camera geek info (old image):

  • William Optics Zenith Star 73 III APO telescope
  • William Optics Flat 73A
  • Canon EOS 60D in manual mode, 2 minute exposure, ISO 1600 and ISO 2000, custom white balance 3500K
  • iOptron CEM40
  • Dell City, Texas Bortle 2-3 dark skies

Frames (old image):

  • June 10, 2023
    • Run 1 1600 ISO
      • 99 2 minute lights
      • 31 0.01 second flats
      • 20 0.01 second flat darks
    • Run 2 1600 ISO
      • 39 2 minute lights
      • 31 0.02 second flats
      • 30 0.02 second flat darks
      • 71 2 minute darks
  • June 11, 2023 2000 ISO
    • 151 2 minute lights
    • 31 0.02 second flats
    • 20 0.02 second flat darks
    • 31 2 minute darks
  • June 12, 2023 2000 ISO
    • 30 2 minute lights
    • 31 0.02 second flats
    • 30 0.02 second flat darks
    • 32 2 minute darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

M46, two Planetary Nebulas, and the Joy of Discovery

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Messier 46, also numbered New General Catalogue (NGC) 2437, is an open cluster, a cluster of about 500 stars that formed from the same molecular cloud and are similar in age, estimated to be 251.2 million years old.  M46 is located in the Milky Way, approximately 4930 light years away, and it has an apparent size of 25.3 arcmin, so it is approximately 36 light years across.  

I chose to photograph this open cluster not only because it is a Messier object I haven’t imaged yet but because there is a planetary nebula in front of it, so I was getting to image two objects at the same time. 

But when I processed the image and removed the stars, I got a surprise.  There wasn’t just one planetary nebula – there were two!  I was delighted and felt the joy of discovery.  I hadn’t known there was a second planetary nebula there, and yet there it was!  I immediately used PixInsight to annotate the image to see if the small planetary nebula was known, and of course it had already been discovered.  But it was still super fun to find something unexpected in my image.

The planetary nebula I had been intending to image, NGC 2438 or PK 231+04.2, is located in the Milky Way, approximately 1377 light years away, and it has an apparent size of 1.173 arc min, so it is approximately 0.5 light years across.  Because it had a different relative motion relative to us than M46, it is not considered to be part of the open cluster.  Before I learned that, I had thought it would be cool if it were part of the cluster and that possibly (since cluster stars are generally of similar age) multiple stars in the cluster could generate visible planetary nebula at the same time.  Wouldn’t that be a sight to see?

My surprise planetary nebula, Minkowski M1-18 or PK231+0.41, is located in the Milky way, approximately 14500 light years away, and it has an apparent size of 0.507 arcminutes, so it is approximately 2.1 light years across.  So further away and larger than NGC2438.

In this image, the stars came from images using red-green-blue filters, and the two nebulas came from images using Hydrogen alpha (mapped to red) and Oxygen iii (mapped to turquoise) filters.  The two nebulas were processed separately to maximally enhance each, which means that they are more equal in brightness in the image than they are in reality (M1-18 is much dimmer).

Have you felt the joy of discovery lately?

Camera geek info – Narrowband:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila SHO and RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • November 23, 2024
    • 135 60 second Gain 150 Ha lights
    • 30 1 second Gain 150 Ha flats
  • December 19, 2024
    • 97 60 second Gain 150 Oiii lights
    • 30 0.5 second Gain 150 Oiii flats
  • December 20, 2024
    • 89 60 second Gain 150 Ha lights
    • 30 1 second Gain 150 Ha flats
  • December 31, 2024
    • 100 30 second Gain 150 Green lights
    • 30 0.02 second Gain 150 Green flats
    • 100 30 second Gain 150 Blue lights
    • 30 0.02 second Gain 150 Blue flats
    • 100 30 second Gain 150 Red lights
    • 30 0.05 second Gain 150 Red flats
  • 30 Flat Darks from library
  • 30 Darks from library

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • NBColourMapper
  • Generalized Hyperbolic Stretch

M31 Andromeda Galaxy Astrophotography Learning Curve

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The first object that I got a satisfactory image of with my tracking mount and telescope and DSLR was M31, the Andromeda Galaxy, from the dark skies of Dell City, Texas in October 2022.  My first image, above, was a 3 minute long exposure.  I was so excited to have a good image that I took a picture of my camera’s viewfinder to send the picture to people.  

When I came home to Friendswood, Texas, I did some experiments to see if I could get the same results.  It was not a surprise when the answer was “no” – my home skies are much more light polluted – I expected to get a completely white screen and was surprised when I could still see a hint of the galaxy.

I started to learn how to use PixInsight, a powerhouse astrophotography processing tool, in the winter of 2022.  I learned enough to be able to stack 18 3 minute images to make my Christmas card photo and the picture I am still using as my computer background at work.

I’ve learned a more about astrophotography processing since then, most notably adding Russ Croman’s excellent BlurXterminator, NoiseXterminator, and StarXterminator tools to my toolbox and learning a ton from Adam Block’s videos.  So I reprocessed the data above using my current knowledge and toolset.

Finally, in October 2024, we were back in Dell City, and I collected new M31 data using an astrocamera and red, blue, green and hydrogen-alpha filters.  I had to learn more in order to be able to merge the Ha data into the RGB data.  Luckily, there are Adam Block’s videos!  One new trick I had to use was “continuum subtraction” – removing the background red from the stars from the Ha data.  

Sometimes, when other things aren’t working out (comet processing), it’s good to step back and see how far you’ve come. I’ve learned a lot over two years … and I’m looking forward to learning a lot more!

What are you learning about?

M27 NGC6853 The Dumbbell Nebula or The Apple Core Nebula

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M27, also called the Dumbbell Nebula or Apple Core Nebula, is a planetary nebula – the gases expelled from a red giant star before it becomes a white dwarf, lit up by that star.  It’s located in the Milky Way, approximately 1250 light years away, and it has an apparent size of 8 arcmintues, making it 2.9 light years across.  It’s estimated to be 12,700 years old.

Planetary nebulae do not last long on an astronomy time scale because the expelled gases grow dimmer as they expand away from the central star.  I am glad I live in a time when we can observe them and they can be observed!

Planetary nebulae were originally called that because they looked like a round (like a planet) ball of fuzz by visual observers.  However, now we know they have nothing to do with planets and are actually shell(s) of gas expelled from a red giant star.  With astrophotography, we can pick up so much more detail than a fuzzball, and so we end up with interesting names.  For this nebula, some thought the inner core of this nebula looked like a dumbbell; others thought it looked like an apple core.  With the outer fringe, what do you think it looks like?

I used data from my driveway in Friendswood, Texas with suburban Bortle 7 – 8 brightness skies (lots of light pollution) to make this image.  In order to capture the outer fringe I needed a lot of data: 12.2 hours of Ha data and 10.65 hours of Oiii data, taken over nine nights.

This is a narrowband image, mapping Oiii to blue and Ha to red.  My goal was to capture both the details in the core and the outer fringe.  It took three processing tries, but I think I was ultimately successful.

Isn’t our galaxy beautiful?

Camera geek info – Narrowband:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila HO filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • June 22, 2024
    • 20 60 second Gain 150 Ha lights
    • 30 0.05 second Gain 150 Ha flats
  • June 28, 2024
    • 47 60 second Gain 150 Oiii lights
    • 30 0.05 second Gain 150 Oiii flats
  • July 3, 2024
    • 100 60 second Gain 150 Ha lights
    • 30 0.05 second Gain 150 Ha flats
  • August 15, 2024
    • 256 60 second Gain 150 Oiii lights
    • 30 0.05 second Gain 150 Oiii flats
  • August 16, 2024
    • 283 60 second Gain 150 Ha lights
    • 30 0.05 second Gain 150 Ha flats
  • August 20, 2024
    • 45 60 second Gain 150 Oiii lights
    • 30 0.05 second Gain 150 Oiii flats
  • August 22, 2024
    • 136 60 second Gain 150 Oiii lights
    • 30 0.05 second Gain 150 Oiii flats
  • August 23, 2024
    • 155 60 second Gain 150 Oiii lights
    • 30 0.05 second Gain 150 Oiii flats
  • August 24, 2024
    • 327 60 second Gain 150 Ha lights
    • 30 0.05 second Gain 150 Ha flats
  • 30 Flat Darks from library
  • 30 Darks from library

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch
  • NBColourMapper

M27 Dumbbell Nebula

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M27 is one of the brighter objects I imaged while we were enjoying the dark skies in Dell City, Texas.  This object was a brilliant blue in a single frame, and it was nice not to have to rely on faith that something was there.  

This image used only 1.8 hours of data. 

M27, also called the Dumbbell Nebula or Apple Core Nebula, is a planetary nebula – the gases expelled from a star before it becomes a white dwarf, lit up by that star.  It’s located in the Milky Way, approximately 1250 light years away, and it’s approximately 2.9 light years across, giving it an apparent size of 8 arcminutes.  It’s estimated to be 12,700 years old.

Planetary nebulae do not last long on an astronomy time scale because the expelled gases grow dimmer as they expand away from the central star.  I am glad I live in a time when we can observe them and they can be observed!

Isn’t our galaxy beautiful?

Camera geek info:

  • Canon EOS 60D in manual mode, 2 minute exposure, ISO 1600
  • Intervalometer
  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • iOptron CEM40
  • Dell City, Texas Bortle 2-3 dark skies

Frames:

  • October 11, 2023 
    • Run 1
      • 54 2 minute lights 
      • 30 0.01 second flats
      • 30 0.01 second flat darks
    • 35 2 minute darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

Astrophotography Makeover: M101 and M16

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M101 with Supernova 2023xif – with and without BXT and NTX

M16 Eagle Nebula – with and without BXT and NXT

After learning about the powerful BlurXterminator (BXT) and NoiseXterminator (NXT) tools, I reprocessed my M101 and supernova and M16 images that I took from the glorious dark skies of Dell City, Texas earlier this summer.  I was amazed that so much detail can be found in images of objects thousands to millions of light years away taken by my small telescope.  

M16:

Camera geek info:

  • Canon EOS 60D in manual mode, 2 minute exposure, ISO 2000
  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • iOptron CEM40
  • Dell City, Texas Bortle 2-3 dark skies

Frames:

  • June 11, 2023
    • Run 1 
      • 6 2 minute lights
      • 31 0.02 second flats
      • 30 0.02 second flat darks
      • 31 2 minute darks
  • June 13, 2023 
    • Run 2
      • 88 2 minute lights
      • 30 0.02 second flats
      • 31 0.02 second flat darks
    • Run 3
      • 83 2 minute lights
      • 31 0.02 second flats
      • 30 0.02 second flat darks
      • 31 2 minute darks
  • 17 frames rejected for a total of 5 hours and 20 minutes of data

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

M101:

Camera geek info:

  • Canon EOS 60D in manual mode, 2 minute exposure, ISO 1600 and ISO 2000
  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • iOptron CEM40
  • Dell City, Texas Bortle 2-3 dark skies

Frames:

  • June 10, 2023
    • Run 1 1600 ISO
      • 99 2 minute lights
      • 31 0.01 second flats
      • 20 0.01 second flat darks
    • Run 2 1600 ISO
      • 39 2 minute lights
      • 31 0.02 second flats
      • 30 0.02 second flat darks
      • 71 2 minute darks
  • June 11, 2023 2000 ISO
    • 151 2 minute lights
    • 31 0.02 second flats
    • 20 0.02 second flat darks
    • 31 2 minute darks
  • June 12, 2023 2000 ISO
    • 30 2 minute lights
    • 31 0.02 second flats
    • 30 0.02 second flat darks
    • 32 2 minute darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXterminator
  • Generalized Hyperbolic Stretch