Monday, August 29, 2011
M16, the "Eagle nebula", reprocessed
Since my processing technique gets better and the time of year doesn't give any support, I have reprocessed some older images. There is now star colors added and other processing is tweaked too.
Merssier 16, in Serpens
Ra 18h 18m 48s Dec -13° 49′ 00″
M16, narrow band HST-palette and a broad band RGB-stars.
Buy a photographic print from HERE
Buy a photographic print from HERE
This is a reprocessed closeup image of the "Eagle Nebula", M16, NGC6611, in constellation Serpens.
Messier 16 is a part of a diffuse H II emission nebula region, IC 4703 at distance of about 6.500 light years.
The region is under an active star formation. The tower of gas, seen middle Right in this image, is approximately 100 trillion km long. (60 trillion miles) The longest of the "pillars" is about seven light years long.
Tips of the pillars are "stellar nurseries", there are several, recently (~one million years ago) formed young stars.
Images are taken with the Northern Galactic group's remote telescope in Australia, from Oulu, Finland. .
Natural color composition from the emission of ionized elements, R=80%Hydrogen+20%Sulfur, G=100%Oxygen and B=85%Oxygen+15%Hydrogen to compensate otherwise missing H-beta emission. This composition is very close to a visual spectrum. Broad band RGB-stars.
Buy a photographic print from HERE
Technical details
16" RCOS ja Apogee U9000 camera.
LRGB combo.
H-alpha 5x1200s, O-III 2x1200s, S-II 2x1200s . Dark and Flat calibrated.
Broad band luminance 15x300s.
RGB-colors Red 2x300s, Green 2x300s and Blue 2x300s.
Raw data is shared with Petri Kehusmaa and J-P Metsavainio
Processing workflow:
Image acquisition, MaxiDL v4.xxx
Stacked and calibrated in CCDStack.
Deconvolution with a CCDSharp, 30 iterations.
Levels, curves and color combine in PS CS3.
An experimental version of M16, narrow band colors with the broad band luminance.
HST-palette colors with a Broad band luminance and RGB-Stars.
Red=S-II, Green=H-a and Blue=O-III
Buy a photographic print from HERE
Natural color narrow band composition with a Broad band luminance and RGB-Stars.
Red=70%Ha+30%S-II, Green=O-III and Blue=70%O-III+30%H-alpha.
In this experimental image, I have tested the method to use a clear filter luminance with a narrow band color. This is (only?*) scientifically correct method to use a luminance image with a narrow band colors, since the broad band luminance contains all the wave lengths used for color information.
I don't usually like to mix colors from a different imaging methods, like pure RGB and narrow band. In this case I have used RGB, real color, stars with an emission line image.
I don't usually like to mix colors from a different imaging methods, like pure RGB and narrow band. In this case I have used RGB, real color, stars with an emission line image.
Some astro imagers tend to use H-alpha channel as a luminance, due the higher details and better S/N than any other channel has. Even though the visual appearance might look better, other channels, O-III and S-II, has no information in H-a luminance and all details in there are lost!
(*I have to point out, I use H-a luminance with a many NB images but H-a is boosted with all the information in O-III and S-II channels used. I call this method "Tone Mapping". Step by step instructions can be found here: http://astroanarchy.blogspot.com/2009/04/neaic.html )
Thursday, August 25, 2011
APOD
![[nasa-large.jpg]](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnPTKmnidt6gHuVkChO_MPYTqp2lSu-Tr0If3ey1qfJxF9BJpDhG8wIWnxo86hb3vT5OYKiznVUminjBaRRat99o70A1ODvDjHEDHpKGWYCsnjn-WFYunaGVPsfXiizriH0upX9hbpNWs/s1600/nasa-large.jpg)
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My Image of the "Pac man Nebula", NGC281, was selected as an "Astronomy Picture of the Day" by the NASA.
You can see the NASA page here: http://apod.nasa.gov/apod/ap110825.html
You can see the NASA page here: http://apod.nasa.gov/apod/ap110825.html
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This was my Fourth APOD, previous ones can be seen here:
Potrait of NGC281
Original blog post, with the technical details and more images, can be seen here:
Wednesday, August 24, 2011
NGC 1499, the "California Nebula" reprocessed, ones again...
I did reprocessed this nebula since my skills are much better now, than two years ago.
All the exposures I have taken for this object are used. Total exposure time is over 20h together for all three channels, Ionized Sulfur, Hydrogen and Oxygen. Two camera lenses was used to capture the data, a Tokina AT 300mm f2.8 and a Canon EF 200mm f1.8, both lenses was used at full aperture.
NGC 1499, in Perseus
Ra 04h 03m 18s Dec +36° 25′ 18″
This object has a very large angular scale, as can be seen in a last image in this page.
It has a lowish surface brightness too, hence 20h of exposures, with fast optics, was needed.
California nebula located in constellation Perseus at distance of ~1000 light years.
California nebula located in constellation Perseus at distance of ~1000 light years.
R=Sulfur, G=Hydrogen and B=Oxygen.
Apparent scale in a sky
This is a large object, note, the size of the Moon is marked, as a scale, in all of the images above.
The Wikipedia article states, that the angular size is about 2,5 degrees (Five full Moons side by side)
but as can be seen in this image, the actual size, with a dim outer parts, is much large.
Experimental 3D-studies of NGC1499 can be found in my portfolio, in different formats.
Please, have a look here:
http://astroanarchy.zenfolio.com/f359296072
The Wikipedia article states, that the angular size is about 2,5 degrees (Five full Moons side by side)
but as can be seen in this image, the actual size, with a dim outer parts, is much large.
Experimental 3D-studies of NGC1499 can be found in my portfolio, in different formats.
Please, have a look here:
http://astroanarchy.zenfolio.com/f359296072
Previous reprocessed version can be seen here:
Sunday, August 14, 2011
Rosette Nebula, apparent scale in a sky, horizontal edition in two palettes
I have shot many targets with several focal lengths.
Due that, I will publish some of my material as an image sets, with different field of view and detail levels.
The fractal nature of our universe stands out nicely by this way and it will make the orientation more easy.
Many times, it's difficult to understand the image scale of astronomical images.
Due that, I will add a Moon circle in some of the images to show the angular scale in a sky.
The full Moon has an angular size of ~30 arc minutes, that's equal to ~0,5 degrees.
"Rosette Nebula"
Ra 06h 33m 45s Dec +04° 59′ 54″, in constellation Orion
Images are in HST-palette, (HST=Hubble Space Telescope)
from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
Star colors are mixed from the NB channels, Red=H-a, G=O-III and B= 85%O-III + 15%H-a.
NOTE. The size of the full Moon (0,5 degrees) is marked as a gray circle in all of the images.
Information about the Rosette Nebula
The Rosette Nebula (also known as Caldwell 49) is a large, circular H II region located near one end of a giant molecular cloud in the Monoceros. The open cluster NGC 2244(Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter. The cluster and nebula locates at a distance of about 5,200 light years from Earth. The diameter is about 130 light years.
The radiation from the young stars ionized the atoms in the nebula, causing them to emit light, typical to each element, producing the visible nebula. Stellar winds, radiation pressure, from a group of stars cause compression to the interstellar clouds, followed by star formation in the nebula. This star formation is currently still ongoing.
Natural color composition from the emission of ionized elements, R=80%Hydrogen+20%Sulfur, G=100%Oxygen and B=85%Oxygen+15%Hydrogen to compensate otherwise missing H-beta emission. This composition is very close to a visual spectrum.
NOTE. The size of the full Moon (0,5 degrees) is marked as a scale.
1. Two panel mosaic of Cone and Rosette Nebulae. Shot with a Canon EF 200mm f1.8 lens, Baader NB-filters and QHY9 cooled astronomical camera.
2. The Rosette half of the mosaic image.
3. Rosette Nebula with a Tokina AT-X 300mm f2.8 lens, Baader NB-filter set and QHY9 astro camera.
4. Rosette closeup with Meade LX200 GPS 12" 2000mm, NB-filters and QHY9 camera.
Technical details for all of the images above, can be found in my portfolio:
http://astroanarchy.zenfolio.com/
Vertical versions can be seen here:
and here:
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