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Friday, November 30, 2018

Dark dust in Cygnus



Mosaic images needs usually a lots of work and time to be ready. Nothing can beats the resolution of a good mosaic image of the large cosmic object. Since it can take even years to have a finalized photo, I'm trying to shoot subframes of the mosaic image as an individual artworks. many of my mosaic images have been published first as a series of subimages, acting as an individual artworks 

Here is one of those subimages, dark dust clouds of Cygnus. It's a part of large Cygnus nebula complex. More accurately, a part of dust ridge dividing North America and Pelican Nebulae.


Dark Clouds of Cygnus
Please, click for a large photo
  


Image is in Natural color palette from the emission of ionized elements, R=Hydrogen + Sulphur, G=Oxygen and B=Oxygen + 10% Hydrogen to compensate the missing H-beta emission.



Position in the large 16 panel mosaic image of NA and Pelican Nebula
Please, click for a large photo



Technical details

Processing workflow

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 @ f10 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 x 2 and SXV-AOL

Astrodon filters,
5nm H-alpha 3nm S-II and 3nm O-III

Exposure times

Total exposure time for the whole 16 panel mosaic image is around 200 hours.


The Giant Cosmic Squid in Mapped colors


I started this imaging project at this autumn season and after a several months I got it ready!
I have published a natural color version few days ago, the result can be seen HERE.

This is a dimmest target I have shot so far! (At end of the post, there is a single 20 min subframe od O-II light.) Total exposure time for the light from an ionized oxygen (O-III) alone was around 35h. Most of the data was shot at binned down to 4x4! For some details I shot about ten hours of 2x2 binned data. H-a is brighter but not bright either. There is about ten hours of H-alpha light exposed. There is very little light from an ionized sulfur, I shot bin 4x4 data about three hours for S-II. Total exposure time used is around 48h

The Celestron Edge 11" telescope with a 0.7 focal reducer has a perfect field of view for this object. This combo delivers a very high quality image from edge to edge. The Apogee U16 can be very challenging to have a good orthogonality and collimation due to very large CCD-shell. 
Ou4, the Giant Squid (Giant indeed, it's 50 light years across)
Please, click for a large image

Image is in mapped colours, from the emission of ionized elements, R=Sulphur, G=Hydrogen and B=Oxygen. The Squid Nebula is visible only at light of an ionized oxygen, O-III



Ou4 in light of an ionized oxygen only
Please, click for a large image

Also stars has been removed to show the actual formation better. Only the central star shines there.



Wider field of views, Ou4 inside the Sharpless 129
Please, click for a large image



The location  in the sky as a relation to the IC 1396

NOTE, a relative size of the full Moon is shown as a white circle at lower right corner.


INFO

The giant Squid Nebula cataloged as Ou4. Nebula was discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's alluring bipolar shape is distinguished here by the telltale blue-green emission from doubly ionized oxygen atoms. The true distance and nature of the Squid Nebula have been difficult to determine. Still, a recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, Ou4 would represent a spectacular outflow driven by HR8119, a triple system of hot, massive stars seen near the center of the nebula. The truly giant Squid Nebula would physically be nearly 50 light-years across.




A single 20 min. calibrated and stretched 4x4 binned O-III exposure 
Please, click for a large image

Image is divided with a bias corrected flat frame and subtracted with master dark. Even after a heavy nonlinear stretching, very little can be seen in this single 20 min. 4x4 binned  light frame.

Animation
Please, click for a large image

This animated GIF shows the Giant Squid Nebula with all three channels, H-alpha, S-II and O-III versus just the light from an ionized oxygen, O-III









Wednesday, November 28, 2018

A Giant Squid, Ou4, imaging project finalized


I started this imaging project at this autumn season and after a several months I got it ready!
This is a dimmest target I have shot so far! Total exposure time for the light from an ionized oxygen (O-III) alone was around 35h. Most of the data was shot at binned down to 4x4! For some details I shot about ten hours of 2x2 binned data. H-a is brighter but not bright either. There is about ten hours of H-alpha light exposed. There is very little light from an ionized sulfur, I shot bin 4x4 data about three hours for S-II. Total exposure time used is around 48h

The Celestron Edge 11" telescope with a 0.7 focal reducer has a perfect field of view for this object. This combo delivers a very high quality image from edge to edge. The Apogee U16 can be very challenging to have a good orthogonality and collimation due to very large CCD-shell. 
Ou4, the Giant Squid
Please, click for a large image

Natural color scheme from the emission of an ionized elements, H-a, S-II and O-III. This is a very large nebula, this image spans horizontally about 1.5 degrees = three full Moons side by side in a sky.


Ou4 in light of an ionized oxygen only
Please, click for a large image

35h of O-III exposures, the Apogee U16 astro camera and Astrodon 3nm O-III filter.
Telescope, Celestron Edge 11"


Wider field of view, Ou4 inside the Sharpless 129
Please, click for a large image

Natural color scheme from the emission of an ionized elements, H-a, S-II and O-III
I have shot the Sharpless 129 nebula, surrounding the Ou4, back at 2013. I combined the new data with the old one and here is the results.

A panoramic view shows the IC 1396, Sh2-129 and Ou4 in same field of view.


Animation


Animated frames, All channels, O-III only  and O-III with no stars.


INFO

The giant Squid Nebula cataloged as Ou4. Nebula was discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's alluring bipolar shape is distinguished here by the telltale blue-green emission from doubly ionized oxygen atoms. The true distance and nature of the Squid Nebula have been difficult to determine. Still, a recent investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, Ou4 would represent a spectacular outflow driven by HR8119, a triple system of hot, massive stars seen near the center of the nebula. The truly giant Squid Nebula would physically be nearly 50 light-years across.




A single 20 min. calibrated and stretched 4x4 binned O-III exposure 
Please, click for a large image

Image is divided with a bias corrected flat frame and subtracted with master dark. Even after a heavy nonlinear stretching, very little can be seen in this single 20 min. 4x4 binned  light frame.





Sunday, November 25, 2018

Clouds of Cygnus


I have been using my large 18-panels mosaic image of the Cygnus Nebula Complex as a map to a some rarely imaged dimmer nebulae in that area. The large mosaic photo was taken with a Canon EF 200mm@f1.8 camera lens. I have shot many interesting areas from that photo with much longer focal length instruments. 

Last few years I have been using an excellent telescope for that task, Celestron Edge 11"  reflecting telescope with 0.7 focal reducer. BTW, this is one of the very best focal reducers I have ever been using! Its build like a tank and optical quality is next to nothing. The reducer cost about as much as an good quality refracting telescope but it's worth of every penny. With this reducer my Apogee Alta U16 camera has a spatial resolution of about one arcsecond per pixel. That image scale is pretty much optimal for my imaging purposes.

This time I picked up an interesting looking object from Cygnus Nebula Complex. This emission nebula is a kind of dim target and I was able to dig out some extreme dim emission from the ionized oxygen too (O-III) I haven't seen any pictures focusing to this nameless target so far.


Clouds of Cygnus
Please, click for a large photo

Image is in mapped colours, from the emission of ionized elements, R=Sulphur, G=Hydrogen and B=Oxygen. The signal from the ionized oxygen (O-III) was very weak.


Visual colors
Please, click for a large photo

Image is in Natural color palette from the emission of ionized elements, R=Hydrogen + Sulphur, G=Oxygen and B=Oxygen + 10% Hydrogen to compensate the missing H-beta emission.


In light of an ionized hydrogen alone (H-alpha)
Click for a large image

H-alpha exposure alone.


Orientation in large context
Click for a large image

he area of interest is marked as a white rectangle.


Technical details

Processing workflow

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 @ f10 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 x 2 and SXV-AOL

Astrodon filters,
5nm H-alpha 3nm S-II and 3nm O-III

Exposure times

H-alpha, 13 x 1200 s, binned 2x2 = 4 h
O-III, 6 x 1200 s, binned 4x4 = 2 h.
S-II, 3 x 1200 s. binned 4x4 = 1 h