PixInsight Forum

PixInsight => Gallery => Topic started by: Geoff on 2015 June 23 03:48:27

Title: NGC 5189, the Spiral Planetary
Post by: Geoff on 2015 June 23 03:48:27
This was taken over 2 new moon periods at my dark sky site  (May and June 2015). I had about 8 hours data, but the seeing was a bit up and down so I tossed out an hour and a half or so.
It's a nice object, but very small--about twice the angular size of Jupiter.
Telescope: 12.5" Plane Wave CDK
Camera: FLI Proline 16803 (Real waste of real estate to get to this heavily cropped pic)
Mount AP900
Exposures: 10 x 10min each of L, R, G and B
FOV: 15' x 11'
Processing: PixInsight

Full res here http://www.astrobin.com/189227/

NGC 5189 (also Gum 47, IC 4274 and nicknamed the Spiral Planetary Nebula) is a planetary nebula in the constellation Musca. It was discovered by the Scottish Australian astronomer James Dunlop in 1 July 1826. For many years, well into the 1960s, it was thought to be a bright emission nebula. It was Karl Gordon Henize in 1967 who first described NGC 5189 as quasi-planetary based on its spectral emissions.

Seen through the telescope it seems to have an S shape, reminiscent of a barred spiral galaxy.
The unusual shape appears consistent with a hypothesis that the dying central star is part of a binary star system with a precessing symmetry axis. NGC 5189 spans about three light years and lies about 3,000 light years away in Musca.
Geoff
Title: Re: NGC 5189, the Spiral Planetary
Post by: Zocky on 2015 June 23 10:47:10
Fascinating object. Regarding image processing I have 2 notes. Image looks to blurry and blue stars have cyan colored cores.
Title: Re: NGC 5189, the Spiral Planetary
Post by: Geoff on 2015 June 23 18:44:11
Thanks Zocky.  The FWHM was around 2.5"-2.7", which is a bit much to give really sharp detail in an image of this size.  As for the stars, I suspect I can fix them with more careful processing.
Geoff