Tuesday, March 19, 2013
Sharpless 261, the "Lower's Nebula"
This starts to be my final images for this season. We'll be out of an astronomical darkness in couple of weeks, up here 65N.
Difficult target just above the Orion, I have spent three night trying to collect enough photons to have a nice image. Sh2-261 doesn't rise very high up here, so I have only around three hours per night to shoot this.
I manged to collect five hours of H-a light and six hours UHCs-filtered colors. 11h total exposure time is not too much for this object.
Sharpless 261 (Sh2-261) , the Lower's Nebula
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III. Colors are shot simultaneously with H-a emission by using QHY8 color camera, Tokina AT-X 300mm f2.8 camera lens and Baader UHCs-filter.
INFO
SH2-261, or Lower's Nebula, is a Hydrogen Alpha emission region located in the upper area of Orion, near the Gemini constellation. Image covers about a same area as a full Moon. There is no information about the distance of this hydrogen cloud, so we are not able to determine how large it is.
The nebula is named after amateur astronomers Harold Lower and his son Charles, who discovered this nebula in 1939 from a picture taken with their homemade 8 inch, f/1 Schmidt camera.
Image in Hydrogen alpha light alone
Technical details
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 7Hz
Image Scale, ~0,8 arc-seconds/pixel
15 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 5h
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Color exposures with QHY8 single shot color camera
36x600s exposures with UHC-sfilter = 6h
36x600s exposures with UHC-sfilter = 6h
Friday, March 15, 2013
Rosette Nebula, a closeup, part II
I have combined the new Rosette data to an old one, from the year 2010.
New image has little different colors and much tighter stars. The natural color image, more or less red, is done by combining colors from wider field Rosette image to a closeup. Wide field image used is shot with Tokina 300mm f2.8 camera optics, UHC-s-filter and the QHY8 color camera. UHCs-filter from Baader delivers natural colors to the Nebula and stars. UHCs-data is shot simultaneously with new image of H-a emission.
Rosette Nebula & a star cluster NGC 2239
Ra 06h 33m 45s Dec +04° 59′ 54″
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III. Colors are shot simultaneously with H-a emission by using QHY8 color camera, Tokina AT-X 300mm f2.8 camera lens and Baader UHCs-filter.
¨
A new data alone
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III. Colors are shot simultaneously with H-a emission by using QHY8 color camera, Tokina AT-X 300mm f2.8 camera lens and Baader UHCs-filter.
A leaping Puma
A detail, from the image above, looks like a leaping puma!
INFO
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.
Rosette closeup in mapped colors
from narrowband channels
Image is in mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
A new data alone
Image is in mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
A wide field image of the Rosette Nebula
Image is in mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
Blog post about the image with technical data:
A study about an apparent scale
Click for a large image!
Note. A moon size circle in the images as a scale. (Moon has an apparent size of 0.5 degrees, that's equal to 30 arc minutes)
Technical details
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 11Hz
Image Scale, ~0,8 arc-seconds/pixel
13 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 4h 20min.
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Data from 2010
H-alpha 13x1200s, binned 1x1
Colors are taken from my older wide field image, for a mapped color composition, and new UHCs-filtered image, for a visual color composition.
emission.
UHCs-filtered image
Shot for color information
This image is used just for the color information. Only 20min. of exposures.
Tokina 300mm f2.8 camera optics, UHC-s-filter and the QHY8 color camera. UHCs-filter from Baader delivers natural colors to the Nebula and stars. UHCs-data is shot simultaneously with new image of H-a emission.
Monday, March 11, 2013
Rosette Nebula, a closeup
The weather up here 65N hasn't been very cooperative. My latest image, the Rosette Nebula, has taken during four different nights, about an hour at the time, before the clouds rolled in. Images are shot at 20.02, 25.02, 07.03 and 08.03. 2013.
I shot just H-alpha channel, other two channels, S-II and O-III are from an older wide field image of the same target.
"Rosette Nebula"
Ra 06h 33m 45s Dec +04° 59′ 54″
Image is in mapped colors from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen.
INFO
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 colors
from narrowband channels
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III.
A wide field image
A wide field image of the Rosette Nebula in visual colors, taken with the Tokina AT-X 300mm f2.8 camera lens and the cooled astronomical camera, QHY9.
Blog post about the image with technical data:
A study about an apparent scale
Click for a large image!
Note. A moon size circle in the images as a scale. (Moon has an apparent size of 0.5 degrees, that's equal to 30 arc minutes)
Technical details
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 11Hz
Image Scale, ~0,8 arc-seconds/pixel
13 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 4h 20min.
Colors are taken from my older wide field image
A single unprocessed 1200 second frame of H-a emission
A single 20 min. frame, just calibrated and nonlinear stretched to visible.
Imaged with the QHY9 camera, Baader 7nm H-alpha filter and Meade LX200 12" telescope.
Tuesday, February 26, 2013
The Veil Nebula, an experimental 3D-study
This is an experimental test with a 3D-conversion of my astronomical images. Only real elements from my image are used, there is nothing added but the volumetric information!
(In this image, some of the stars are enhanced for a visual reasons)
NOTE. This is a personal vision about shapes and volumes, based on some scientific data and an artistic impression.
Veil Nebula supernova remnant as a 3D-model
In constellation Cygnus, animation in natural colors
This is a looped video, click to start and stop. Original movie is in HD1080p resolution.
An other version of the animated Veil
Animation in mapped colors
This is a looped video, click to start and stop. Original movie is in HD1080p resolution.
My original image of the Veil Nebula is used for the animations
Click for the large image
Blog post about this image with technical details:
http://astroanarchy.blogspot.fi/2012/03/veil-nebula-reprocessed-with-some-new.html
An animated GIF
Click for a large image
Blog post about the animated GIF can be seen here:
http://astroanarchy.blogspot.fi/2012/10/an-experiental-3d-animation-from-my.html
My original image of the Veil Nebula is used for the animations
Click for the large image
As can be seen here, the compression in YouTube has lost some details from above videos, they are all in original, less compressed, video.
Blog post about this image with technical details:
http://astroanarchy.blogspot.fi/2012/03/veil-nebula-reprocessed-with-some-new.html
An animated GIF
Blog post about the animated GIF can be seen here:
http://astroanarchy.blogspot.fi/2012/10/an-experiental-3d-animation-from-my.html
HOW IT'S DONE
For as long as I have captured images of celestial objects, I have always seen
them three-dimensionally in my head. Over time I realized that we actually have
enough scientific information to build a coarse skeleton model of the nebula itself.
The scientific information makes my visions much more accurate, and the 3-D technique I have developed enables me to share those beautiful visions with others.
How accurate my 3-D-visions are depends on how much accurate information I have and how well I implement it. Also, many different estimates are
needed for the 3-D model. The final 3-D-image is always an appraised simulation
of reality based on known scientific facts, deduction, and some artistic creativity
on top of everything else
After I have collected all the necessary scientific information about my target,
I start my 3-D conversion using the stars in the image. 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
then 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. So it
is the nebula itself that is glowing, at the characteristic wavelengths of each ionized element. (The principle is very much the same as in fluorescent tubes.) I use
this information for my 3-D model. 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 pillarlike 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 nebula, otherwise we can’t see it.
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
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