PN Shapley 1

The Fine Ring Nebula

0.32 light years.
4,900 light years.
Apparent size:
1.1 arc min

Shapley 1 is a faint annular planetary nebula in the southern constellation of Norma. At magnitude 12.6, it proved elusive until I ramped up the gain level to be certain that I was aiming my telescope in the right direction. Presenting as a ring, astronomers suspect that its structure is cylindrical and aligned towards Earth. Its age has been estimated at around 8,700 years.

It is the second time I’ve imaged Shapley 1. The previous time was when I was using my DSLR camera, before I acquired an astro-camera.

The central star, a white dwarf from which the nebula was ejected, is clearly visible.

I took this image using my planetary camera, which is uncooled. Hence I had to deal with some pretty awful amp glow and other high gain camera noise, some of which still remains after processing the image. I also forgot to use an optical filter.

Shapley 1 is only a few arc-minutes from a second planetary nebula which I imaged on the same night, called Stephenson 1. Image to follow.

61 minutes
Field of View:
18.5 x 12 arcmin
Image date:

Two big news items in astronomy this week:

1. Gravitational Waves

LIGO announced the detection of the first observations of a black hole/neutron star pair. Not just one pair but two separate pairs, ten days apart!

The LIGO gravitational wave detection observatories are the most astonishing instruments, on a par with the Large Hadron Collider and exquisitely sensitive. Incredible human achievements, both of them!

This was an exciting discovery, from a truly amazing observatory – but it will be eclipsed in a few years time by the discoveries made by the following new telescope:

2. The SKA

The Square Kilometre Array (SKA) radio telescope will be the largest telescope of any kind ever built and will reveal in detail many hidden secrets of the Universe.

This week it was announced that the construction phase of the SKA will begin. The SKA will be constructed in South Africa and Australia – and Phase 1 will consist of two telescope arrays: 197 dishes in South Africa and 131,072 low frequency antennae in Western Australia.

Four years ago I got to examine one of the low frequency antennae prototypes:

2017-02-20: I had the privilege of handling an MWA Antenna, courtesy of Dr Emil Lenc (Sydney Uni) at Macarthur Astronomy Forum. Image by John Rombi.

Location of Constellation

Location of Norma constellation, courtesy Wikipedia Commons and Sky & Telescope

Thanks for reading 🙃

Telescope & Imaging Details

Telescope:SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.
Optics:Field flattener; no filter.
Mount & Guiding:SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.
Imaging camera: ZWO ASI 290 MC uncooled.
Software:Control: Cartes du Ciel, ASCOM, EQMOD, PHD2. Imaging: SharpCap, Gimp.
Observatory:34° South.

Images © Roger Powell

I’m one of the founder members of Macarthur Astronomical Society and current webmaster.



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Sydney Solar Eclipse


  1. Very nice captures both times of this ring. It is a lot dimmer than M57 that I am more familiar with.

    I read about the SKA project. Very interesting. I look forward to seeing results. I agree how incredible the LIGO systems are. It is a new age of discovery.

    Liked by 1 person

    1. It’s tempting to try M57 with the planetary camera and see if it’s effective…..

      I first learned about the SKA about ten years ago. Australia was then hoping it would all be built here but it was not to be. We just got the low frequency array. It is so advanced and of such a huge scale that it will produce incredible amounts of data, more than they can permanently store. Modern computing systems are yet to reach the processing speeds that will be required!

      I think fourteen countries are currently part of the consortium.



        1. That decision was taken by the US a few years ago when the SKA organisation began to ask nations to formally commit. I’m not sure if it was Bush or Obama. I think the US did have some early involvement prior to that. It all comes down to $$$$.

          However, new nations have been signing up and it’s not too late.

          Liked by 1 person

  2. I hadn’t heard about the LIGO discovery (I’d used LIGO in one of my short stories way back when, long before I had this blog). Nice.

    As for the annular nebula (neat photo, by the way) . . . why would they suspect it’s cylindrical? I’ve never heard of a naturally occurring cylindrical assembly of gasses. it seems to fly in the face of what we know about gravity and how it acts on matter.

    Liked by 1 person

    1. Planetary nebulae come in many strange shapes and sizes. Torus shaped planetaries are often suspected of having considerable depth along the line of sight. It’s probably related to gas being ejected mostly from the equatorial region of the central star. I wish I could answer your specific question but I can’t.



      1. Hmmm . . . considerable depth is subjective and doesn’t elicit an image of cylindrical shape . . . more like a thick torus. Forming of a ring (and eventually a spherical envelope) makes sense, so that might be in transition.

        Still, if cylindrical shapes occur, wouldn’t they present themselves as rectangles in a side view? Have we imaged any rectangular nebulas?

        There’s one that’s actually a double cone that I’m sure you know of ( but that’s the only one I know of, and it’s not a true rectangle like a cylinder would appear.

        But, I’m beating a dead horse . . . until we can form a wormhole and travel to check it out, anything we say is pure conjecture.

        Liked by 1 person

    1. If you do that, she may be impressed – but if she then made further enquiries she would discover that the constellation was not named after a lady of beauty but after the Latin name for a draughtsman’s set square. Not so romantic!

      However, there is also an asteroid named Norma, discovered by a man named Max Wolf. He discovered 248 asteroids and most of them were named after ladies. He must have enjoyed an extensive love life…..

      Liked by 1 person

      1. Ha, that’s even better! Now I can also annoy a Norma if I wish. 😁 Personally, I find it fascinating that’s where “Norma” originated in this context. I love tracing the paths of names and words back through time.

        Liked by 1 person

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