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Monday, March 4, 2019

Simeis 147 closeup, my last photo for the Spring season 2019

This is my last photo for ongoing season. Well served Celestron Edge 11" telescope went back the Celestron seller. They borrowed it to me back in 2014 and make possible to me to continue my imaging work. It was a great instrument, especially equipped with the Celestron 0.7 reducer for the Edge telescope. This system was able to cover the large CCD in Apogee alta U16 camera. The field of view was about one square degree and the image scale was optimal to my conditions, about 1 arc second per pixel. I'll publish later a collection of images taken with this combo.
With this setup, I got three APOD images published by NASA.

Now I need to find a new scope for the next season. One possible way to go is buying a second hand medium format camera lens. In medium format lens the image circle is large enough to cover the large CCD-shell in Apogee Alta U16 camera. Also I need a tool for a longer focal length work. 

Simeis 147, a supernova remnant in Taurus
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 dim and diffused nebula, this image spans vertically about one degrees (= two full Moons side by side in a sky.)

An experimental starless view
Please, click for a large image

The shapes and details in actual nebula are much easier to study in this starless version.


Simeis 147 (sharpless 240), is a very faint and very large supernova remnant in constellation Taurus at distance of ~3000 light years. It's constantly expanding at speed of 1000 km/second but due the size of it, we can't see any movement in it. This SN spans over 160 light years and the apparent scale in the sky is about three degrees (Moon has an apparent size of 30" = 0,5 degrees).  Explosion took place approximately 30.000 years ago  and left behind a  pulsar (Neutron star). The pulsar has recently identified.

An older wide field photo of the Simeis 147 SNR
Please, click for a large image

An area of the new photo is marked as a white rectangle. The actual remnant is much large as can be seen in this photo from 2011. photo is taken with a Canon EF 200mm f1.8 lens, baader narrowband filters and the QHY9 strocam. More info HERE

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

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, 33 x 1200 s, binned 2x2 = 11 h
O-III, 15 x 1200 s, binned 4x4 = 5 h.
S-II, 9 x 1200 s. binned 4x4 = 3 h
Total exposure time, 19h

Single 20 min. calibrated and stretched exposures 
Please, click for a large image


2x2 binned H-alpha frame is divided with a bias corrected master flat and subtracted with a master dark. 


4x4 binned S-II frame is divided with a bias corrected master flat and subtracted with a master dark. 


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

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