Orion's got cavities!

By Phil Plait | October 26, 2011 7:00 am

The Orion Nebula is perhaps the most famous gas cloud in the sky. And no wonder: it’s easily visible to the unaided eye, it looks fuzzy and diffuse even in binoculars, in small telescopes its shape can be discerned, and in long time exposures its beauty is devastating. The delicate wisps and tendrils, the bold colors, the odd shape… it’s got it all.

I’ve seen hundreds of pictures of it, and there’s almost always something new to see. But I don’t think I’ve ever seen a shot of it quite like this:

Isn’t that incredible? It was taken by Jesus Vargas (Astrogades) and Maritxu Poyal [click to ennebulenate]. Amazingly, it was taken with a telescope that had a lens only 10.6 cm (4") across! But the nebula is so bright that it doesn’t take a big ‘scope to get great images of it (though, to be fair, Takahashi makes very high quality ‘scopes).

What I like about this image is how obviously it shows that the nebula is actually a giant cavity in space. The actual cloud is far larger than what you see here, very dense and dark. But many stars are forming in the heart of the Orion Nebula, and a handful of them are massive and hot. Their ultraviolet radiation has flooded the interior of the cloud, eating away at it, carving out a huge divot light years across, and lighting it up. What you’re seeing here is more tenuous gas filling that cavity.

I love that. When I was younger I thought the nebula was just this diffuse puffery floating out in space, but reality is — as usual — more interesting, more profound, and more awesome than what we might first think. Images like this really drive that home.

Vargas and Poyal have several other images of this magnificent gas cloud, including this slightly wider field-of-view, one with different color filters, and one with a much wider field-of-View. These are all magnificent, and well worth your time looking at.

I’ve written about this nebula many times, as you might expect. Check out the Related posts links below for lots more info on this fantastic object.

Image credit: Jesus Vargas and Maritxu Poyal, used by permission.

Related posts:

A new old view of an old friend
The unfamiliar face of beauty
C-beams off the shoulder of Orion
A dragon fight in the heart of Orion

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (18)

  1. Pete Jackson

    Incredible views! And it’s amazing how the appearance changes so much with different filters.

    By the way, “this slightly wider field-of-view” is a bad link, but the other links are fine.

  2. Kirk Aplin

    Great headline.

  3. Nigel Depledge
  4. Excellent view! I always love pictures of the Orion Nebula. I wish I could read that site. the animation near the top right is very cool too. I

  5. ‘scope

    Is this a stupid-looking smart quote?

  6. Joel

    I love the Orion nebula, even with the naked eye.

    It also gives me a good opportunity to go into a tangentially related anecdote. See, the Orion nebula makes for a good example of just how little most space-related conspiracy theorists (ancient astronauts, etc) really know about the night sky. I was looking up things about the Mayan beliefs about the nebula, having just seen The Fountain, when I found a website which claimed that as the Mayans knew it was a fuzzy cloud rather than a normal star, which of course had to prove that at the very least the Mayans must have had advanced technology, and most likely had been visited by aliens who gave it to them.

    Which struck me as odd, because where I grew up, in a place with reasonably but not extremely dark skies at night, it was very easily visible as a small fuzzy blob to the naked eye, and quite distinct from most other objects visible in the night sky. To the Mayans, without any light pollution at all, it must have been even more distinctive.

    I live in a city now, and one of my biggest regrets about the light pollution has been the shrinkage of the nebula to a point-like appearance. Ah well, enough rambling.

  7. New Desktop background! Wish I could see it with the naked eye. Shanghai is simply too dirty and too bright. Next time I’m back in PA maybe…

  8. The image is quite beautiful. It was stated that the Orion nebula is visible to the naked eye, but I have never seen it with my own eyes in the night sky. Then again, I don’t recall ever really looking for it. But either way, the sight of the image is quit magnificent.

    I wanted to mention something I have a question about concerning the “new” nebula. It was mentioned in the post that stars are forming in the heart of the cloud and have flooded it with their ultraviolet radiations, resulting in a cavity in the nebula. I thought the stars we see are many years old because of the time it takes the light wavelengths to travel to Earth. Doesn’t that mean then that the stars we are seeing in the heart of the nebula are actually many years old, and are thus not forming stars? Could that then mean we are seeing a cavity formed in the Orion nebula from the past, and that the “new” light in the nebula is also many years old?

  9. Joel

    @9 Tyler LeQuia: Yes and no. With astronomy, people tend to talk about objects as they can be observed from Earth, as trying to establish what has happened to them in real time would obviously be (admittedly educated) speculation. The Orion nebula is around 1344 light years away, so we’re seeing it now as it would have been in around AD 667, including the cavity. Things will certainly have changed a bit in there by now, but a millennium or so isn’t very long at all in terms of stellar or nebular lifetimes, so it won’t be drastically different, either.

    I’ll meet you here in the year 3355 so we can have another look, ok? :)

    But it definitely is visible to the naked eye. Next time you get a clear night and Orion is visible, have a look at Orion’s Sword, just underneath the three stars of the Belt. The nebula is in the middle of it. And if it’s clear and dark where you are, you should be able to see that it’s a small fuzzy patch rather than a point like the other stars.

  10. Infinite123Lifer

    I am glad Orion does not regularly floss or brush! :)

  11. When I was younger I thought the nebula was just this diffuse puffery floating out in space

    Me too … I remember anticipating the first Hubble pictures, wondering how the promised photographs of nebulae could possibly be better than the ones we already had … which were beautiful, but also, well, nebulous. I had no idea. I thought they were supposed to look like colourful puffs of gas.

    Hubble gave us nebulae that looked like solid sculptures, or at least swirls of liquid. It seems obvious in hindsight, but I never expected that.

  12. Derek

    Sure, it’s beautiful in the sky but if you’d found that on your carpet you’d be renting a steam cleaner.

  13. Thank you very much. We are very happy with this APOD

  14. Wow. Great picture. :-)

    @9. Tyler LeQuia :

    The image is quite beautiful. It was stated that the Orion nebula is visible to the naked eye, but I have never seen it with my own eyes in the night sky. Then again, I don’t recall ever really looking for it. But either way, the sight of the image is quit magnificent.

    If it helps Messier 42 (& Messier 43 which is a separate part of it. Seen combined in the sky) – as the Great Orion nebula is also known – is in Orion’s sword or the middle of the “handle” of the Saucepan asterism* as seen from the Southern hemisphere.

    Click on my name for a photographic finder chart via Jim Kaler’s Stars website.

    Oh & good luck. Not that you’ll likely need it – M42-M43 is pretty obvious as a fuzzy star in all but the most light polluted skies.

    * Orions belt = the bottom of the saucepan.

  15. (Had to rush off & couldn’t finish the asterisked note above there.)

    * The Saucepan asterism is made up from the Belt stars – from Sirius facing side to the Taurus facing side : Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis) & Mintaka (Delta Orionis) – which make its base, with Saiph al Jabbar (Eta Orionis) :


    marking the corner opposite the handle and the handle being three stars the lower one, the Orion nebula and then Iota Orionis also known as Hatsya or Na’ir al Saif :


    which is the uppermost star at the end of the handle.

    This link :

    also provides a good photographic “skymap” of Orion in case that helps. :-)

  16. .. the handle being three stars the lower one,..

    Being C Orionis or (Flamsteed number?) 42 Orionis – I think – info. on it, specifically, proving rather difficult to find :


    See also :


    for Theta-1 Orionis the stars of the Trapezium cluster that illuminate the Orion nebula &


    for old time illustration skychart showing how the Hunter figure was traditionally seen plus some the mythology for the constellation courtesy of Ian Ridpath.

    Plus click on my name for link to Kaler’s page on HR 1988 a double exoplanet hosting yellow sub-giant star located near Orion’s belt on a line between Alnitak & Betelguese.

  17. Isaac

    It’s too bad we can’t get a couple of big telescopes far enough apart to get a 3D image of this.


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