Tuesday, November 4, 2014
NGC 281, the Siamese fighting fish
At 31. October I shot the raw frames for the NGC 281. Yesterday I combined them as a final color photo. When the photo was ready, I didn't saw the usual "Pac Man" figure but a Siamese fighting fish!
Image in visual colors
It does look like a Siamese fighting fish!
INFO
NGC 281 is an H II region in the constellation of Cassiopeia. It includes the open cluster IC 1590 and several Bok globules (dark doo-dads at center of the Blue area). NGC 281 is also known as the Pac-Man Nebula for its resemblance to the video game character from early 80's. NGC 281 spans over 80 light years at its estimated distance of 9500 light years.
A study about the structure
All pillar like formations are pointing to a source of ionization, the open cluster NGC 281. There are some more dense areas in a gas, able to resist the radiation pressure from young star cluster. Those dense areas, at a tip of the each pillar, are also potential places for the formations of the new stars. Note. There are some very dim outer formations in this nebula, I haven't noticed them before. Like the one pillar like at the eleven o'clock position.
A starless view
An experimental starless view shows better the actual structure of the nebula.
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 50% 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
Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar x2
Astrodon filter, 5nm H-alpha
Astrodon filter, 3nm O-III
Exposure times
Astrodon filter, 3nm O-III
Exposure times
H-alpha, 9 x 1200s = 3h
O-III, 3 x 1200s = 1h
S-II, 3x1200s = 1h
S-II, 3x1200s = 1h
A single un cropped, calibrated and stretched 20 min. H-alpha frame
A sample image of Tonemapped channels
I'm using a special processing technique of mine for a weak signal, the Tone Mapping v2
Starless emission channels are much easier to process for color channels since I don't need to worry about bloating stars etc. In HST-palette, the idea is to have all the channels in equal weight in the final color image. To do that, tens of times more exposure time is needed for a weaker channels, usually O-III or S-II. Typically it's not possible in any reasonable time frame and weaker channels needs to be stretched very strongly. Doe to that, lots of artifacts are generated, like purple stars. With my technique a perfect color balance is easily done.
Sunday, November 2, 2014
Sharpless 115 and a planetary nebula Abell 71
I have always wanted to shoot this complex nebula and planetary in Cygnus. The object is kind of dim and has lots of details. Actually it's so complex, that I had a hard time trying to figure out how to make a nice composition out of it.
Sharpless 115, Sh2-115 and Abell 71
A square of birth and death
Click for a large image
Closeups from the image above
Abell 71, PLN 85+4.1
Image in visual colors
A starless version
INFO
Source: NASA APOD
Sharpless 115 stands just north and west of Deneb, the alpha star of Cygnus the Swan in planet Earth's skies. Noted in the 1959 catalog by astronomer Stewart Sharpless (as Sh2-115) the faint but lovely emission nebula lies along the edge of one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. Shining with the light of ionized atoms of hydrogen, sulfur, and oxygen in this Hubble palette color composite image, the nebular glow is powered by hot stars in star cluster Berkeley 90. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115. But the stars' strong winds and radiation have cleared away much of their dusty, natal cloud. At the emission nebula's estimated distance, this cosmic close-up spans just under 100 light-years.
Orientation
More info about this image can be seen HERE.
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 50% 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
Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar x2
Astrodon filter, 5nm H-alpha
Astrodon filter, 3nm O-III
Exposure times
Astrodon filter, 3nm O-III
Exposure times
H-alpha, 18 x 1200s = 6h
O-III, 6 x 1200s = 2h
S-II, 3x1200s = 1h
S-II, 3x1200s = 1h
A single un cropped, calibrated and stretched 20 min. H-alpha frame
Friday, October 31, 2014
The Cygnus Wall
A fast image from the last night, the Cygnus Wall, a part of the much large North america Nebula, NGC 7000. This is a relatively bright formation, three hours of H-alpha light and half an hour of O-III was captured for this photo. S-II channel is borrowed from an older wide field image, since the clouds rolled in before I was able to shoot it.
Click for a large image
Detail from the image above
INFO
Source: NASA APOD
The North America nebula on the sky can do what the North America continent on Earth cannot -- form stars. Specifically, in analogy to the Earth-confined continent, the bright part that appears as Central America and Mexico is actually a hot bed of gas, dust, and newly formed stars known as the Cygnus Wall. The above image shows the star forming wall lit and eroded by bright young stars, and partly hidden by the dark dust they have created. The part of the North America nebula (NGC 7000) shown spans about 15 light years and lies about 1,500 light years away toward the constellation of the Swan (Cygnus).
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 50% 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
Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar x2
Astrodon filter, 5nm H-aplha
Astrodon filter, 3nm O-III
Exposure times
Astrodon filter, 3nm O-III
Exposure times
H-alpha 6 x 1200s = 3h
O-III 3 x 600s = 30min.
S-II is borrowed from my older wide field image
A single un cropped, calibrated and stretched 20 min. H-alpha frame
A single un cropped, calibrated and stretched 20 min. H-alpha frame
Wednesday, October 29, 2014
Tulip Nebula, the finalized project
I made a deeper view of the Tulip Nebula (Sharpless 101, Sh2-101) by adding some more exposure time.
There are now nearly 9h of H-alpha exposures integrated. I exposed couple of hours new O-III but most of the colors are from an older wider field image of mine.
Tulip Nebula, Sh2-101
in constellation Cygnus, click for a large image
A detail from the image above
A microquasar Cygnus X-1
Shown in a starless image
I removed all the stars but the microquasar Cygnus X-1. It can be seen as a bright dot at upper right.
The curved bow shock structure can be seen in the image above, just left from the microquasar itself.
INFO
Source: NASA APOD
What happens to matter that falls toward an energetic black hole? In the case of Cygnus X-1, perhaps little of that matter actually makes it in. Infalling gas may first collide not only with itself but with an accretion disk of swirling material surrounding the black hole. The result may be a microquasar that glows across the electromagnetic spectrum and produces powerful jets that expel much of the infalling matter back into the cosmos at near light speed before it can even approach the black hole's event horizon. Confirmation that black hole jets may create expanding shells has come recently from the discovery of shells surrounding Cygnus X-1. The physical processes that create the black hole jets is a topic that continues to be researched.
Tulip Nebula in visual palette
Emission channels are composed to match to a visual spectrum. If you like to have a photographic print, click HERE
H-alpha emission alone
A wide field image of the area
Colors for the new image are partly from this wide field shot. Original data can be seen HERE
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 50% 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
Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar
Astrodon filter, 5nm H-aplha
Astrodon filter, 3nm O-III
Astrodon filter, 3nm S-II
Exposure times
Astrodon filter, 3nm O-III
Astrodon filter, 3nm S-II
Exposure times
H-alpha 26 x 1200s = 8h 40 min
O-III 6 x 600s = 1h
S-II 6x 600s = 1h
A single un cropped, calibrated and stretched 20 min. H-alpha frame
A single un cropped, calibrated and stretched 20 min. H-alpha frame
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