Barnard's beauty

By Phil Plait | October 14, 2009 8:00 am

The Local Group of galaxies is our Milky Way’s neighborhood: a few dozen galaxies dominated by our own, as well as Andromeda and a handful of largish ones.

But by far the majority of galaxies in our group — the majority everywhere, really — are dwarfs; small collections of stars and gas with only a few million stars. Lurking just 1.6 million light years away, half the distance to Andromeda, is Barnard’s galaxy, an irregular dwarf with about 10 million stars. Behold!

[As usual, click to embiggen, or get a ginormous 80 Mb TIF.]

This is perhaps the finest near-true color image of Barnard’s galaxy I have ever seen, courtesy of the European Southern Observatory’s 2.2 meter telescope in Chile… a far cry from the small 12.5 cm (5 inch) refractor Barnard himself used to discover it. Given that this diminutive galaxy is in the direction of Sagittarius — toward the center of our galaxy, which is loaded with stars — it’s incredible Barnard found it at all. In fact, most of the stars in this image are inside the Milky Way, between us and the other galaxy.

Barnard’s Galaxy is not precisely irregular, since it appears to have a bar-like structure across it. The red bubbles are regions where stars are being born in large numbers; the UV and fierce winds of subatomic particles from the massive stars being formed carve out cavities in the gas, creating what look like smoke rings. The red glow is characteristic of hot hydrogen, and is a sure-fire way to know that gas is being excited by the stars nearby. The sharp edges to the bubbles are real, due to the gas piling up as it rams gas in interstellar space in a cosmic snowplow effect. There are over 150 separate bubbles like these in the galaxy, some of which have been observed using the Hubble Space Telescope.

There is another feature here that’s not obvious. On the left and right of the galaxy are faint, thick, blue arcs. This is actually gas that’s being blown out by the stars in the center of the galaxy, forming a weak ring surrounding the entire structure. I expect that gas will blow right out of the galaxy entirely; the gravity from the meager number of stars making up Barnard’s Galaxy can’t possibly be enough to restrain it.

Dwarf galaxies are difficult to observe because they are so faint; they fade with distance rapidly, so only nearby ones can be studied in detail. But since they are the most numerous types of galaxy in the Universe, these tiny smudges are well worth studying, and images like this one of Barnard’s Galaxy will help us understand how these galaxies formed, and what they’re made of, and how they behave. We also think that through collisions, these galaxies can grow to become larger, more magnificent ones like our Milky Way, so, as usual, when we study the Universe, looking ever outward, we are actually turning our gaze inwards to learn more about ourselves.

Image credit: ESO.

CATEGORIZED UNDER: Astronomy, Pretty pictures
MORE ABOUT: Barnard's Galaxy, ESO

Comments (29)

  1. Ray M

    Clicking on the image gets you to an authentication request…

  2. Ken

    Yup, I have sent Phil an email that (hopefully) he gets, including an attached image of the authentication box. The ESO article is located at: http://www.eso.org/public/outreach/press-rel/pr-2009/pr-38-09.html and the images seem to work for me from here…so i don’t think that it’s private/public directory issue (as far as logging in). Maybe they don’t allow direct linking to images on their site. In that case, i’d just upload it here if Discover allows it.

  3. CJSF

    1/2 the distance to Andromenda, but towards the center of our galaxy? Somehow that seems less clear than it could be. Also, if it’s 1/2 the distance to Andromeda, but toward the center of our galaxy, that means it’s on the other side of the Milky Way than us?

    Amazing photo, though. The universe is so freakin’ amazing! Thanks for another awesome Astronomy post, Phil.

    CJSF

  4. CJSF, it’s half as far away, but not towards Andromeda. Like saying that Boston is Half the distance from New York than Richmond, VA (rough approximation).

    This is the same Barnard that has his own star too, right?

  5. DemetriusOfPharos

    As has been noted, the links to the image provided don’t seem to work. This is the page I found for the images, and there is a sidebar on the right for different resolutions/file types:
    http://www.eso.org/gallery/v/ESOPIA/Galaxies/phot-38a-09-fullres.tif.html

    I didn’t see a 40 meg jpg, the large jpg I downloaded was a little over 2 meg. There was, however, and 80 meg tiff.

  6. Inajira

    Awesome picture, Phil. Can’t help wondering if someone on one of those stars is looking back at us. That goes for any galaxy, for that matter.

  7. Sorry about the links. This was an embargoed press release and still under wraps when I wrote the post, and while I was careful to make sure the link to the release itself was active, I didn’t check the image links! Those have been fixed.

  8. kevbo

    @Inajira

    ..you mean, will be looking back at us? Or is that, is looking back at…homo erectus? Or.. oh, whatever…

  9. Helioprogenus

    Do these galaxies have supermassive black holes at their center like the larger spiral and elliptical types? Is there a theoretical galactic size and shape needed for their formation? If Bernad’s doesn’t have it, do the Large and Small Magellanic Clouds have them centrally located?

    I assume that in these slightly irregular galaxies, stars revolve around a certain point? Are they just generally static or is there a common direction of motion?

  10. All the imagery coming out of the ESO is just incredible. This is one more reason why we should support science. I set this up so you can explore the image. Enjoy!

  11. Some of the foreground stars appear as disks. Are we really seeing the disk of those stars or is it an artifact?

  12. Yeah, ESO has been on a roll lately. Man. I feel like I should send them a thank-you note for all the beautiful images! Instead I think I’ll just keep showing them to my coworkers and trying to expand the audience.

  13. mike burkhart

    As always this picture is incredable it the next thing to being there in person (wicth would take you millons of years to get there even at the speed of light to get there so untill warp drive is invented we will have to settel for photos )

  14. CJSF

    @4 (Larian),

    Yes, I know what he meant, but it just isn’t as clear (to me) as it could be. To me, saying something is at some distance toward the center, it implies that it is between us and the center. That would mean it is inside our galaxy. If it’s half the distance to Andromeda, on the other side of the Milky Way, I feel there could be an clearer way to say it. Espcially for those of us still struggling to get a grip on these huge distances.

    CJSF

  15. CJSF, AH, I see what you are saying. I think he meant looking in the general direction of the center of our galaxy as opposed to some other direction (so looking towards the constellation Saggatarius).

    (Andromeda) ——————————–(Milky Way)
    ………………………………………………….^———–
    ………………………………………………….|…………….————–Barnard
    …………………………………………………..US

    (Yes, I know, the schematic sucks, I did it in just a few seconds!) So not quite looking at the center (a little off, otherwise we couldn’t see it), but in the general direction.

  16. WFB

    For us poor folks still forced to use slow dial-up, it would be nice if your JPG of the galaxy had been compressed at 70-80% rather than the 100% quality on this page. That way we could get the entire image to download! It’s 368.48 KB as is. I can get it to 92.24 KB at 75% in Fireworks. It is just common courtesy.

  17. WFB, I usually compress images, but with big splashy ones it degrades the quality substantially and makes it less likely people will get excited about the picture. I can only do so much to support people on dialup, using text browsers, and so on without making it a poorer experience for everyone else. I have to compromise somewhere, and so I do it with the rare big pic like this one.

  18. llewelly

    How did Barnard get both a dwarf star and a dwarf galaxy named after him?

  19. IVAN3MAN AT LARGE

    @ Larian LeQuella,

    You’re right, that schematic sucks; it’s also wrong! I’ll show you how it’s done…

    On a 24 hour clock, the Galactic Center is at coordinates 17h 45m 40.04s; the Andromeda Galaxy is at coordinates 00h 42.44m 30s, and NGC 6822 (Barnard’s Galaxy) is at coordinates 19h 44m 56.6s.

    The image below illustrates the positions of the galaxies in the local group:

     

    Image Hosted by ImageShack.us
    The Local Group of Galaxies.
    (Click on the image to Zoom In and Out.)
  20. Cory

    @11, as mentioned in the post, most of the stars in the picture are actually members of our own galaxy, and thus are relatively close when compared to Barnard’s.

  21. Plutonium being from Pluto

    Given that this diminutive galaxy is in the direction of Sagittarius — toward the center of our galaxy, which is loaded with stars — it’s incredible Barnard found it at all.

    Edward Emerson Barnard was a superluminous (ie beyond just brilliant!) astronomer who I consider to be one of the greatest observers ever and an inspirational astronomy hero. He had exceptional eyesight and spotted craters on Mars at a time many were struggling to spot Lowell’s non-existant “canals”. Barnard also had a fascinating and moving life story coming from a very poor background.

    E. E. Barnard discovered the eponymous star, the second closest to our Sun, and was, I think, the first person to discover a comet photographically. He also discovered many other comets, Jupiter’s moon Amalthea – the first found around that planet since Galileo’s moons – and, of course, the galaxy seen here but is perhaps most famous for his catalogue of dark nebula which was published 90 years ago. For more see :

    http://en.wikipedia.org/wiki/Edward_Emerson_Barnard

    Although I’d also highly recomend reading William Sheehan’s superb biography ‘The Immortal Fire Within : The Life and Work of Edward Emerson Barnard’ (Cambridge University Press, 1995.) of Barnard’s life.

    Barnard’s Galaxy is not precisely irregular, since it appears to have a bar-like structure across it.

    Reminds me of the Large Magellanic Cloud which similarly often gets mislabelled an irregular despite having some barred spiral structure to it.

    Great photo & post as always – thanks BA. :-)

  22. Messier Tidy-Upper

    @ 19. IVAN3MAN AT LARGE Says:

    You’re right, that schematic sucks; it’s also wrong! I’ll show you how it’s done…

    On a 24 hour clock, the Galactic Center is at coordinates 17h 45m 40.04s; the Andromeda Galaxy is at coordinates 00h 42.44m 30s, and NGC 6822 (Barnard’s Galaxy) is at coordinates 19h 44m 56.6s.

    Thanks for posting that galactic map here. At first I couldn’t find Barnard’s Galaxy then I read the text again and realised it was down as an NGC number. Three things stuck me here :

    1) Yikes – Barnard’s Galaxy sure seems a lot better easier to remember than another acronmyn and set of numbers!* Let’s please all settle on using the name ‘Barnard’s Galaxy’ everywhere shall we?

    2) Hmmm .. Looks like Barnard’s Galaxy is pretty close to halfway between the Milky Way and Andromeda galaxies and their satellite groups. If we were on aplanet in Barnard’s galxy looking up -how bigand bright would the Milky Way and Andromeda seem – would we get a great view tocompare them or what! :-D

    &

    3) Hang on a minute NGC = New General Catalogue which is now actually very old and was published a little while after Messier’s original one. Was Barnard’s discovery really included there or added later? Plus was E.E. Barnard actually one of the people who helped compose the NGC? I thought that was mainly John Drayer using Herschel’s data in Europe rather than the USA right? See http://en.wikipedia.org/wiki/New_General_Catalogue . So what’s Barnard’s Galaxy doing in the NGC listing?

    Thanks again though – great map! :-)

    —-

    * Yeah, I know the Messier catalogue uses M + numbers too but, hey, at least it only goes up to 110 & doesn’t use ‘new’ when its old! Besides I’m sure you’ve heard that quote about “consistency being the bugbear of small minds” right? ;-)

  23. nobody

    “Barnard’s Galaxy is not precisely irregular, since it appears to have a bar-like structure across it. ”

    I can’t see the bar-like structure in the photo :( Can anyone else see it?

    By the way, the stellar nurseries (red bubbles) look like small fireworks going off!!!! It’s so cool…

  24. StevoR

    @ 18. llewelly asked:

    How did Barnard get both a dwarf star and a dwarf galaxy named after him?

    By discovering both of them and much, much more!

    This is from an article I wrote for the Astronomical Society of South Australia monthly newsletter :

    ***
    Edward Emerson Barnard was one of the great 19th and 20th century astronomers. He overcame an impoverished start to life to make a number of significant discoveries including Jupiter’s moon Amalthea, 16 comets, and over 300 deep sky objects, mostly dark nebulae, but also including the Rosette and California nebulae. He pioneered wide-field astrophotography as well as making the first ever photographic discovery of a comet. E. E. Barnard personally estimated that he had observed every astronomical object possibly visible to him at least 100 times. Barnard has the eponymous star plus a Galaxy and numerous nebulae named after him. A summarised chronology of his career follows :

    1857 Born in the slums of Nashville, Tennessee, to a poor family.

    1866 Begins work in photographic studio aged nine. He only ever had two months formal schooling but proceeds to teach himself from second hand books.

    1876 Barnard buys his first telescope, a 5-inch refractor, costing eight months worth of wages.

    1881 Discovers his first comet.

    1883 Obtains scholarship to Vanderbilt university

    1884 August 17th observes the Galaxy now bearing his name.(NGC 6822)

    1887 Barnard shifts to the Lick Observatory of the University of California having graduated with a Bachelors degree in maths and having discovered eight comets.

    1892 Discovers the fifth moon of Jupiter – Amalthea –using the 36 inch Lick refractor. Also in this year, E.E. Barnard makes the first ever photographic discovery of a comet.

    1895 Joins Yerkes observatory staff in Wisconsin and is involved in ground-breaking studies of dark nebulae.

    1916 Barnard discovers the extreme proper motion of Munich 15040 which is then named Barnard’s Star in his honour.

    1919 Publishes the first catalogue of dark nebulae.

    1923 Barnard dies aged 66.

    Sources :
    Jakiel, Richard ‘The Man Who tracked Nebulae’, in ‘Astronomy’ magazine May 2001.(Pages 52-57)

    ‘B’ Volume, World Book Encyclopedia, World Book Inc. 1992. (Page 114)

    Further reading : ‘The Immortal Fire Within : The Life and Work of Edward Emerson Barnard’ by William Sheehan.
    (Which is available to read – but not to borrow – from the Bray Reference library section of the State Library. In Adelaide, South Australia.)

    ****

    PS. Woo-Hoo! Seems I can post from home again!
    BA, if you’ve fixed it for me – thankyou, its very much appreciated! :-D

  25. Plutonium being from Pluto

    @ 23. nobody Says:

    “Barnard’s Galaxy is not precisely irregular, since it appears to have a bar-like structure across it. ”

    I can’t see the bar-like structure in the photo Can anyone else see it? By the way, the stellar nurseries (red bubbles) look like small fireworks going off!!!! It’s so cool…

    Yes, I can see it.

    The bar structure is the rectangular shape of the main mass of bluish stars there. In essence, the whole galaxy is a bar shaped rectangle with fuzzy edges and a few pink blobs embedded too.

    It does indeed remind me of the same sort of broad shape with the LMC.

    – StevoR aka PbfP. :-)

  26. nobody

    I can see the rectangular shape, but I’m afraid it doesn’t look much like a bar to my untrained eyes :(

    Thanks for the help Plutonium though!

  27. Phil wrote:

    “I expect that gas will blow right out of the galaxy entirely; the gravity from the meager number of stars making up Barnard’s Galaxy can’t possibly be enough to restrain it.”

    Ah! But what about the graviational contribution from the DARK MATTER within Barnard’s Galaxy? Would that be enough to tip the balance?

  28. Plutonium being from Pluto

    @ 26 nobody : No worries, my pleasure. :-)

    @ 27 tracer : I’m not sure if Barnard’s Galaxy even has dark matter. I think I heard somewhere that concentrations of dark matter might just be limited to larger galaxies – then again I could well be wrong there. Does anyone know?

  29. Chip

    Beautiful picture!
    Here’s some childlike (not childish) questions:
    1. Dwarf galaxies tend to be irregular or with faintly detected structures but how small can a clearly formed spiral or barred spiral or spherical galaxy be?
    2. Are dwarf galaxies sometimes the result of stars thrown out from large galaxy collisions and eventually coalescing or do they usually form on their own? Phil’s article implies they can grow to become full-sized galaxies.

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