Lagoon Nebula M8

2021-05-19 NGC 6523 M8 Lagoon Nebula Stack_16frames_

NGC 6523

Magnitude: +6.0Diameter: 113.6 light years.
Apparent size: 90 x 40 arc minDistance: 4,300 light years.
Constellation: Sagittarius

Whole Sky

Location of the Lagoon Nebula in the sky, about 24° South of the celestial equator, in the constellation of Sagittarius.

Sky mapping Images courtesy of:


Location of the Lagoon Nebula M8.

The Lagoon is an emission nebula over four thousand light years away in the flat plane of the Milky Way galaxy. It is an intense star forming region, with many hot, young ‘baby’ stars already established in the nebula, their ultra-violet light ionising the atomic hydrogen (HII). The ionised atomsemit light at a wavelength of 656.3 nm, giving a characteristic red colour. The filter I used is tuned to this HII wavelength.

The small dark regions are Bok globules where gas in the region has condensed and multiple embryonic stars are forming inside.

At last! My first night outside with the telescope after a successful surgical procedure and over six weeks of rest and recovery. Fortunately my sky remained clear all evening, despite the threat of a bank of high flying clouds.

The main astro-news of the week seems to be the eruption of a nova in the constellation of Cassiopeia. A nova is a sudden transient brightening of a star in a close binary system. I wish I could see it but I will leave that to northern hemisphere observers, as it it will not rise in my southern sky.

Elsewhere, there will be a total lunar eclipse next week (26th May), visible here in Australia during the evening. It coincides with a full moon (of course!) and a lunar perigee, so standby for a few days of ridiculously over-hyped Moon names from the media (and even some astronomers who ought to know better). Forget the silly names, it’s a lunar eclipse – and it’s worth a look. It’s great to be back with my telescope again and I will be photographing the eclipse – if the sky remains clear.

Feature image date:2021-05-19
Exposure:62.5 minutes (16 x 234 sec)
Field of View:87.1 x 58.1 arcmin

If the Astrometry images do not appear it is because the Astrometry website is sometimes off line.

Telescope & Imaging Details

SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.
Field flattener; ZWO Duo-band Hα (656nm) and [OIII] (500nm) filter.
SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.
Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).
Software: Telescope control: Cartes du Ciel, EQMOD, PHD2, Imaging: SharpCap, Gimp.
Observatory location: 34° South.

Thanks for reading!

Images © Roger Powell

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


  1. Welcome back with your scope and equipment. That is a beautiful image of M8. I might get a very brief glimpse of partial eclipse. I don’t have any clever names for this one to pass along. 🙂

    Liked by 1 person

  2. Welcome back. So glad you are better and out under the stars. That sounds like lyrics to a song.
    Be sure to take your Bride too. Fran


  3. Welcome back and nice image of M8! Unfortunately for me Nova Cas is too low now but would have been a great spectroscopy target. However I do believe we will be able to see the eclipse just as the Moon is setting here in the Southwest US. You will have a better view there!


    1. Thanks for your comment. I’m no longer a morning person so its great to have a mid-evening eclipse to look forward to. I guess you’ll see it setting in the West near sunrise time.


  4. Stunning! I can see why it’s called the Lagoon Nebula. It actually looks a bit like a crab to me. 😅

    Yeah, I’m getting a bit tired of all the moon names. Full moons and eclipses are awesome, but the names stopped feeling special when every single one got hyped.

    Liked by 1 person

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