Lonely galaxy is lonely. But it ate its friends.

By Phil Plait | March 8, 2010 7:00 am

Do cannibals have friends? I imagine some must… unless they have them over for dinner.

Just like the giant elliptical galaxy ESO 306-17, which you can see in this gorgeous Hubble picture:


[Click to embiggen, or grab the monster 3800 x 3800 pixel version. They have wallpapers, too.]

ESO 306-17 sits about a billion light years from Earth. In this picture it looks like it’s surrounded by other galaxies, but that’s an illusion: all the other galaxies you see here are either much closer to us or much farther away. ESO 306-17 is actually a loner, sitting all by itself in space.[Update: Or almost all alone; Michael West, who led the team that took these images, tells me the little elliptical at the bottom left of ESO 306-17 may be interacting with it. It’s difficult to tell; but what is certain is that there are very few galaxies near the big one, far fewer than you’d expect.]

How can a galaxy get this big and yet be sitting in a giant void? Easy. It ate all the neighbors. We know this is how galaxies grow in size, and is even why the Milky Way is a giant among galaxies. Like our galaxy, ESO 306-17 has a lot of globular clusters around it, just as you’d expect if it ate a bunch of other galaxies.

When I downloaded the bigger image, I noticed this weird galaxy on the left:


Wow. I’m guessing that long stretched-out junk is a small galaxy that got shredded, maybe after a close pass to that spiral. I thought for a moment the spiral might be active — that is, the black hole in its core was actively eating matter and ejecting long jets of gas and light — but the core itself is not bright, as you’d expect. Plus, the material is lumpy and irregular, more indicative of a cosmic collision in progress. It’s unrelated to the elliptical, but still very cool.

I really urge you to download the big image and take a nice, long look at it. There’s a lot to see, and it’s all really beautiful.

Image credit: NASA, ESA and Michael West (ESO)

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (34)

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  1. I’m guessing some of those spiral galaxies are closer? If so, then that is one beastly galaxy. No wonder it has no friends! It’s hogging the camera, sheesh. <3 Hubble.

  2. Messier Tidy Upper

    Awesome image & write-up there – thanks. :-)

    ESO 306-17 doesn’t look lonely to me – it looks satiated. Or, in other words, full. Very full.

    Might I suggest the name : The Hannibal Lecter galaxy for it?

    Or worse, the disgusting obese Gluttony Guy from Seven Galaxy?
    ( http://en.wikipedia.org/wiki/Seven_(film) )

    A serious question or three if anyone could enlighten us please :

    1) Is it visible in a medium size telescope (say 10 inch Meade?) – what is its apparent magnitude and position?

    2) Is it an Active Galactic Nucleus type – does it have jets and strong radio, UV, X-ray or Gamma ray emissions showing major activity as you might expect from its “eating” binge?

    3) How is its gravity effecting the nearby clusters – please tell me its not drawing us in! :-O

  3. Chris

    I had friends over! But I eated them… :(

  4. ND

    And what is ceiling galaxy doing?

  5. Mapnut

    I for one am sick of all this talk about galaxies “eating” other galaxies! (It’s ruining my life!) 😉 It’s not like it’s digesting them and turning them into stellar poop. All those stars are just moving into a new neighborhood, and life is going on. How about “annexing” instead of eating?

  6. Cindy

    What, no fava beans and Chianti comments? 😉

  7. ND


    How about mergers and acquisitions?

  8. Pi-needles

    5. Mapnut Says:

    I for one am sick of all this talk about galaxies “eating” other galaxies! (It’s ruining my life!)

    Err .. Sorry to hear that but .. *How*?? (Puzzled.)

    @ 4. ND Says:

    And what is ceiling galaxy doing?

    Ceiling galaxy – which one is that? Given that space (& our cosmos) has NO up or down how can you tell “ceiling galaxy” from “floor galaxy?”

    Or am I missing something here?

  9. Pieter Kok

    Mapnut and ND, if you look at the mice galaxy, clearly the partners are being stripped of their assets.

  10. Protological nazi

    No wonder that bloated, gluttonous, cannibal galaxy, ESO 306-17, is lonely and shunned by all the other galaxies – it is sitting in the centre of its own massive (post-digestive process) Void! Ewww! 😉

    (Disgusting, I know but sorry I couldn’t resist.)

  11. Vernon Balbert

    Ceiling Galaxy is a reference to Ceiling Cat. Ceiling Cat is the cat above who watches you do bad things:


    Correspondingly there’s Basement Cat who makes you do bad things:


    So it figures that there’s a Basement Galaxy that made this galaxy eat up his neighbors.

  12. Chip

    What accounts for the evenness, apparent dustless overall smooth and diffuse appearance of the zillions of stars in ESO 306-17 (aside from the bright core)? It appears gigantic yet devoid of obvious clusters, dust, nebulae.

    And yes, the many galaxies behind and in front of it are beautiful.

  13. I don’t know about Ceiling Galaxy but…



  14. Navneeth

    Chip, this one is an elliptical galaxy — it’s more or less an “Old Age Home” sort of place. Here, you won’t see much activity like star formation (which gives rise to dust clouds and bright reflection nebulae and such).

  15. kevlar

    The “haze” of a billion stars makes me wonder if any planet there even knows what night is.

  16. Ad Hominid

    “Might I suggest the name : The Hannibal Lecter galaxy for it?”

    Nah, the Alferd Packer Galaxy. Alferd was a real person after all and his, er, dinner guests had been his traveling companions if not exactly friends.

    Packer is a legend in popular culture of course. My favorite line from the whole story was the alleged statement by the judge upon pronouncing sentence, “”Stand up, Alferd Packer, you voracious, man-eating, (deleted). There were seven Democrats in Hinsdale County, and you ate five of them.”
    These days, the introduction of this political angle would almost certainly be grounds for appeal.

  17. From the press release: “In this image, taken by the Advanced Camera for Surveys aboard Hubble in November 2008…” And I have to say this is the first image I’ve seen (other than the “first light” one) taken with the repaired Advanced Camera for Surveys. Yee-haw! Shore is purty!

    It looks like a very low surface brightness, which means you need a very low background to get a good image. Hubble being above the glow of the sky helps a lot, but you still need a really low-noise camera to get a clean picture. And ACS is even lower noise after the repair than it was when brand new!

  18. Josh


    I agree with you that the smaller “shredding event” you noticed is just that: the result of a galaxy merger. More evidence can be seen in the the lower lefthand quadrant of the spiral galaxy itself, perhaps more noticeable without “embiggenation”. It is possible to trace the tidal tail back to a second galactic bulge that appears to be passing through the plane of the other galaxy at that location. The tidal tail appears connected in much the same way as the tadpole galaxy:


  19. GT

    Two cannibal galaxies were eating a clown galaxy. One turns to the other and asks, “Does this galaxy taste funny to you?” Ba-da-bump!

  20. ND

    Ceiling cat iz whuching ovr ur galakseez.

  21. DMD

    Johnny Vector, the data can’t be taken in November 2008. ACS broken down in January 2007, and it was fixed in May 2009. There should be a typo on the press release text.

  22. @kevlar:
    Sure they would. The difference between night and day is a matter of degree. Most of these deep space images require long exposures precisely because relative to the amount of light that our star gives us during the day time, other celestial objects appear quite dim. If you look up at the night sky and see the band of the Milky Way, you know that it is filled with stars beyond human comprehension and yet it would be foolish to suggest that they produce the illusion of day.

    If you are close enough to a star, it can easily outshine the billions or trillions of companions that comprise the rest of the galaxy.

  23. John Paradox

    ‘it ate its friends’ reminds me of an old joke:

    all flesh is grass
    smoke a friend!


  24. GT @ 18, if there IS a clown galaxy, I hope it gets eaten.

    The galaxy in the second image is clearly firing a barrage of missiles at its neighbors. When will they ever learn?

  25. Chip

    Thanks for the explanation Navneeth.

    I also like the cool rotating video with eerie SciFi music (Krel musicians) on the space telescope website Phil links too above. Great stuff.

  26. Pi-needles

    @ 11. Vernon Balbert Says:

    Ceiling Galaxy is a reference to Ceiling Cat. Ceiling Cat is the cat above who watches you do bad things:

    13. Lewis Says:

    I don’t know about Ceiling Galaxy but… Ceiling cat is still watching you.

    Thanks! That’s cool – and Lewis that’s one big cat there! Great juxtaposition & image. :-)

  27. Waiter: “Perhaps Mssr (Messier?) would be interested in a thin Milky Wafer?”

    Late to the party. Python references, anyone?

  28. The extremo pix you can download now from Hubble let anyone explore as if they had camera time on Hubble. This is why, in my opinion, Hubble is the best investment NASA has ever made. Getting out of the atmosphere trap is the key.

  29. DMD: D’oh, you’re right. Somehow it seems like it’s been a lot more than a year since the mission. I guess that’s because I really stopped working on it in October 2008, when it was supposed to launch (before the SIC&DH failed), and just took a short return to HST-land in May of last year for the launch and mission. Or maybe it’s because time passes differently when you’re not working for Frank Cepollina!

    I see the caption now says it was taken in 2005. So still pre-failure. So imagine what this would look like with 20% less video noise!

  30. Gary Ansorge

    13. Lewis:

    Cats and galaxies have (at least) one thing in common(besides both being composed of star dust); if something is moving in their vicinity, it’ll get trapped and eaten,,,


    Gary 7

  31. Andrew

    The first picture is absolutely gorgeous. The central object almost reminds me of viewing a globular cluster through a backyard telescope. Nice article Phil.

  32. That 1st picture is one of the best Astronomy pics I’ve seen for a long time. The definition seems too good some how and it looks three dimensional.

    “Lonely galaxy is lonely. But it ate its friends.”

    Great title!


  33. Alan

    I wonder how many billions or trillions of sentient beings (if any – depends on unknown Drake equation factors) lost their lives in that event.

    Similary when our galaxy meets its fate with Andromeda distant observers will not know of or hear our cries of anquish. Well if not our cries, then perhaps the cries of some future civilization that is today represented by some simply multicelluar creature somewhere in our galaxy or in Andromeda.

    I’m not seriously suggesting that we should mourn that which we do not even know exists or would even be capable of identifying with. But I’m just saying….


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