Owl Nebula M97

[Star101]

The wonderful weekend continues

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From WiKi - 

The Owl Nebula (also known as Messier 97, M97 or NGC 3587) is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major.[2] It was discovered by French astronomer Pierre Méchain on February 16, 1781.When William Parsons, 3rd Earl of Rosse, observed the nebula in 1848, his hand-drawn illustration resembled an owl's head. It has been known as the Owl Nebula ever since.

The nebula is approximately 8,000 years old. It is approximately circular in cross-section with a little visible internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch. The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell. The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.

The nebula holds about 0.13 solar masses of matter, including hydrogen, helium, nitrogen, oxygen, and sulfur; all with a density of less than 100 particles per cubic centimeter. Its outer radius is around 0.91 ly (0.28 pc) and it is expanding with velocities in the range of 27–39 km/s into the surrounding interstellar medium.

The 14th magnitude central star has since reached the turning point of its evolution where it condenses to form a white dwarf. It has 55–60% of the Sun's mass, 41–148 times the brightness of the Sun, and an effective temperature of 123,000 K.The star has been successfully resolved by the Spitzer Space Telescope as a point source that does not show the infrared excess characteristic of a circumstellar disk.

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This morning, around 01:30 I started imaging M97. I managed 14 x 600s and processed in Pixinsight.

Equipment was C11 @2800mm, Atik 4120EX OSC, Lodestar X2 Guide Cam on ZWO OAG. All mounted on the Mesu 200.

Thanks for looking.

 

 

[rl]

Nice shot.

I'm intrigued about the whiteness of the nebula not characteristic of emission lines; is this a processing artefact ?

I also like the other incidental features like the galaxies to the left and the fan shaped nebula around the star on the right.

[Star101]

1 hour ago, rl said:

Nice shot.

I'm intrigued about the whiteness of the nebula not characteristic of emission lines; is this a processing artefact ?

I also like the other incidental features like the galaxies to the left and the fan shaped nebula around the star on the right.

The whiteness is a combination of the camera and my processing. Stretching the image too much can and will reduce the colour of somethings and make them whiter than they are. Bleaching the colour sometimes. I have another camera that gives different colours again. Also, it has been shown several times recently that if you give 10 people the same image data to process then you will get 10 different coloured and contrasting images. I tend to prefer a brighter background than some others. I can make the background darker to make the image prettier but I do prefer detail and not so much aesthetics   

Christophe has posted the info on the other galaxies and artifact on his M97 here

 

[Star101]

5 hours ago, rl said:

I'm intrigued about the whiteness of the nebula not characteristic of emission lines; is this a processing artefact ?

I decided to go back and reprocess this image as I too was intrigued by the colour. I found that using the STF drag to HTF in Pixinsight can reduce the colour in some images. So I went back to my old method of manually adjusting the Histogram. Adjusting separately the RGB, to align each peak to the others. Stretched and Noise reduced. Colour enhanced. AutomaticBackgroundExtractor applied.

Here is the resulting image.

Thanks for looking.

 

 

Edited December 2, 2019 by Star101