Monday, October 4, 2021
Three 3D-conversions out of my astronomical photos
I have made dozens of 3D-conversions out of my astronomical photos. As an artist I like to find a new views to the reality. My models are not just a guesswork, the conversion is based on real scientific data.
At the end of this blog post there is a short explanation, how I do my conversion work.
Veil nebula in O-III light alone
Original astronomical photo about part of the Veil nebula SNR in O-III light only.
3D-study of Veil Nebula Photo
NGC1499 the California Nebula
My photo of California Nebyla in mapped colors
3D-study of California Nebula Photo
Bubble Nebula
3D-study of Bubble Nebula Photo
How 3D-models are made
My Moleskine notebook pages from 2008, I planned how to convert nebulae to 3D
How accurate my 3-D-visions are depending on how much information I have and how well I implement it.
The final 3-D-image is always an appraised simulation of reality based on known scientific facts, deduction, and some artistic creativity.
After I have collected all the necessary scientific information about my target, I start my 3-D conversion from stars. Usually there is a recognizable star cluster which is responsible for ionizing the nebula. We don’t need to know its absolute location since we know its relative location. Stars ionizing the nebula have to be very close to the nebula structure itself. I usually divide up the rest of the stars by their apparent brightness, which can then be used as an indicator of their distances, brighter being closer. If true star distances are available, I use them, but most of the time my rule of thumb is sufficient. By using a scientific estimate of the distance of the Milky Way object, I can locate the correct number of stars in front of it and behind it.
Emission nebulae are not lit up directly by starlight; they are usually way too large for that. Rather, stellar radiation ionizes elements within the gas cloud and the nebula itself is glowing light, the principle is very much the same as in fluorescent tubes. The thickness of the nebula can be estimated from its brightness, since the whole volume of gas is glowing, brighter means thicker.
By this means, forms of the nebula can be turned to a real 3-D shape. Nebulae are also more or less transparent, so we can see both sides of it at the same time, and this makes model-making a little easier since not much is hidden.
The local stellar wind, from the star cluster inside the nebula, shapes the nebula by blowing away the gas around the star cluster. The stellar wind usually forms a kind of cavity in the nebulosity. The same stellar wind also initiates the further collapse of the gas cloud and the birth of the second generation of stars in the nebula. The collapsing gas can resist the stellar wind and produces pillar like formations which must point to a cluster.
Ionized oxygen (O-III) glows with a bluish light, and since oxygen needs a lot of energy to ionize it, this can only be achieved relatively close to the star cluster in the nebula. I use this information to position the O-III area (the bluish glow) at the correct distance relative to the heart of the nebula.
Many other small indicators can be found by carefully studying the image itself. For example, if there is a dark nebula in the image, it must be located in front of the emission one, otherwise we couldn’t see it at all.
Using the known data in this way I build a kind of skeleton model of the nebula. Then the artistic part is mixed with the scientific and logical elements, and after that the rest is very much like creating a sculpture on a cosmic scale
Thursday, September 30, 2021
Filaments of Veil Nebula SNR
I shot most of the lights for this image back in 2016, now I have added some new material to it and reprocessed the whole image. An older mapped color version can be seen here, https://astroanarchy.blogspot.com/2016/12/filaments-of-veil-nebula.html
Photo was shot with a Celestron Edge HD 11" telescope, Astrodon naarrow band filters and Apogee Alta U16 astro camera. New data is shot with a shorter focal length instrument, Tokina AT-x 300mm f2.8 camera lens, same camera and filters. Dim background emission is taken from a new material and added to this photo.
Total exposure time is now 44 hours for the whole three frame mosaic and the resolution is 11.000 x 4000 pixels.
Filaments of central veil
Click for a large image (1100 x 2900 pixels)
Image is in visual palette from emission of an ionized elements, hydrogen (H-alpha), sulfur (S-II) and oxygen (O-III). Red=Hydrogen + 33% sulfur, Green=oxygen and Blue=oxygen + 33% hydrogen to compensate otherwise missing H-beta emission.
A closeup
Click for a large image
Orientation
Click for a large image
Unveiling the Veiled
Every single pixel in this 3d-animation is from the original 2D-image above. The model is based on on known scientific facts, deduction and some artistic creativity. The result is an appraised simulation of reality. Astronomical photos are showing objects as paintings on a canvas, totally flat. In reality, they are three dimensional forms floating in three dimensional space. The purpose of my 3d-experiments is to show that and Give an idea, how those distant objects might look in reality. More info about my 3D-technique at end of this blog post: https://astroanarchy.blogspot.com/2021/10/unveiling-veiled.html
NOTE. It looks like that the animation has less stars, than the original 2d-image. That's not true, stars is normal photo are getting projected to a same plane. In 3D-model stars are in volume and it only looks like, that there are less stars.
Tuesday, September 28, 2021
Veil nebula unveiled II
I haven't start the imaging season yet, up here 65N. Nights are still short and I haven't got my imaging rig ready after the mandatory six months Summer break.
I have reprocessed some older shots with new data, this time the Veil nebula supernova remnant in Cygnus. Original image was shot with the Canon EF 200 mm f1.8 camera optics full open, QHY9 astro camera and Baader narrowband filters at 2013.
New data is shot with Tokina 300mm f2.8 camera optics and Celestron Edge HD 11" telescope, Apogee Alta U16 astro camera with Astrodon narrowband filters.
Total exposure time is now about 45 hours. I published yesterday a Pickering's Triangle photo taken with Celestron Edge HD 11"-. It's part of this new image among other.
Veil nebula Unveiled
Click for a large image, 1250 x 1700 pixels
Image is in visual palette from emission of an ionized elements, hydrogen (H-alpha), sulfur (S-II) and oxygen (O-III). Red=Hydrogen + 33% sulfur, Green=oxygen and Blue=oxygen + 33% hydrogen to compensate otherwise missing H-beta emission.
A Closeup
Click for a large image
https://astroanarchy.blogspot.com/2013/12/veil-nebula-unveiled.html
Monday, September 27, 2021
Pickering's Triangle in Visual palette
I have reprocessed some older data and made a new composition out of it. Pickering's Triangle is part of the Veil nebula supernova remnant in constellation Cygnus. It has an amazing structure of complex gas filaments. This image is one of the most detailed presentations, showing the whole triangle shape formation, I have seen so far.
Image is in visual palette from emission of an ionized elements, hydrogen (H-alpha), sulfur (S-II) and oxygen (O-III). Red=Hydrogen + 33% sulfur, Green=oxygen and Blue=oxygen + 33% hydrogen to compensate otherwise missing H-beta emission. (H-beta and H-alpha has a same shape but H-beta is weaker. H-alpha emits red light and H-beta emits blue light.) Exposure time ~20 hours.
here you can see ta mapped color image from same data, https://astroanarchy.blogspot.com/2021/08/pickerings-triangle-reprocessed-with.html
Pickering's Triangle with some new lights
click for a large image
click for a large image
Image is in visual palette from emission of an ionized elements, hydrogen (H-alpha), sulfur (S-II) and oxygen (O-III). Red=Hydrogen + 33% sulfur, Green=oxygen and Blue=oxygen + 33% hydrogen to compensate otherwise missing H-beta emission.
A Closeup
click for a large image
The complex structure of gas filaments
Orientation in Veil nebula SNR
click for a large image
Orientation in Veil nebula SNR
click for a large image
Technical details
Processing work flow
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Deconvolution with a CCDStack2 Positive Constraint, 33 iterations, added at 33% weight
Color combine in PS CS3
Levels and curves in PS CS3.
Imaging optics
Celestron Edge HD 1100 @ f7 with 0,7 focal reducer for Edge HD 1100 telescope
Mount
10-micron 1000
Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar x2 and SXV-AOL
Astrodon filter, 5nm H-alpha
Astrodon filter, 3nm O-III
Astrodon filter, 3nm S-II
Exposure times
H-alpha, 15 x 1200s = 5h
O-III, 36 x 1200s binned = 12h (Autumn 2014)
S-II, from my older wide field photo of the Veil Nebula = 3h
Total 20h
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