Rudolph the red-dusted Strömgren sphere

By Phil Plait | December 23, 2011 10:48 am

For some reason, a lot of gorgeous pictures are being released after I post my Top 24 Deep Space Pictures of 2011 gallery. Figures. Since I already had a few images from NASA’s WISE observatory in the gallery anyway I guess can’t complain too much, especially when they release one as pretty as this!

[Click to infraredenate.]

This is Barnard 3, a dusty, gassy region of the galaxy about a thousand light years away where young stars are lighting up their neighborhood. WISE observes the skies in the far infrared, well past what our eye can detect, so this false-color picture mostly picks out the dust warmed by nearby stars. What you see as green and yellow-green is actually from long, complex molecules similar to soot, called polycyclic aromatic hydrocarbons or PAHs. Red shows cooler material.

So what’s going on here? Right in the center of the red splotch is a star which is brighter and hotter than our Sun, and is flooding the surrounding material with ultraviolet light and a fast wind of subatomic particles (like the Sun’s solar wind, but a whole lot stronger and with a much, much farther reach). This has carved out a gigantic cavity in that stuff, creating a bubble about 25 light years in diameter — that’s huge: 250,000,000,000,000 kilometers across, more than 10,000 times the size of our solar system!

The UV from the star is making the gas glow, but that’s not visible in this infrared picture; in optical light (the kind we see with) this object is a mess (see here, for example), with gas emitting light, reflecting light, and dust absorbing it. When gas is lit up this way around a star, it’s called a Strömgren sphere, after the astronomer Bengt Strömgren who did the first theoretical work on them.

All in all, it’s lovely, isn’t it? The folks at NASA and WISE are getting into the spirit of the season, billing this picture of Barnard 3 as a wreath, but I think they missed a good bet: it looks a lot more like a reindeer of fable to me. It even has antlers! Well, kinda.

And perhaps a bigger picture should be drawn here; as we near the end of the year, we approach the beginning of a new one. What better way to get into that spirit than to see a place in space where young, vigorous stars are announcing their presence? Hopefully, 2012 will be filled with energy, warmth, color, and as always more amazing science.

And since I mentioned it earlier, take a look back at the deep space pictures I chose as my favorites in 2011, including no fewer than three from WISE! That gallery is below.

Image Credit: NASA/JPL-Caltech/WISE Team


CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: Barnard 3, dust, infrared, PAHs, WISE

Comments (15)

  1. I hear the other strömgren spheres wouldn’t let it play in their strömgren sphere games.

  2. Robert

    What a beautiful picture. And it does look like a wreath.

  3. Those of us of Germanic descent SALUTE you for caring enough to include the umlaut. I mean, Umläut. Frohe Weihnachten. I mean, Fröhe Weihnachten.

  4. John

    You say the red star is cooler than the Sun? So this is false-color, but red is still hotter than normal red? Just checking.

  5. OtherRob

    Maybe you just need to wait ’til early January 2013 before posting your “Best of 2012” galleries. 😉

  6. John(4): The star lighting up the cloud is actually much hotter than the Sun. If you click the pic to get the bigger version, you’l see it looks blue, but that’s false-color too. This gets confusing. :) It would be blue-white to our eyes, but it’s blue here because it puts out more short wavelength IR light than long wavelength. The way the colors are set up in WISE images, the shorter stuff is blue, the longer stuff red.

  7. The guy’s first name is Bengt, not Bernt.

  8. Crux Australis

    “Strömgren sphere” is inordinately difficult to say.

  9. Phil, which pics would you take out of the running to include these new ones? Be happy they waited so you can include these next year.

  10. Anchor

    This was one of the many dark nebulae catalogued by E.E. Barnard, an astronomer who was an outstanding astrophotographer and observational artist. Here’s his own photo of the region in which the object catalogued “B 3” resides, in Perseus:

    B 3 is that compact little ‘peninsular’ dark nodule just left of the center intruding into the cleared area, much like the Horsehead does.

    His Photographic Atlas of Selected Regions of the Milky Way, was published posthumously by Yerkes Observatory after his death in 1923:

  11. To the tune of .. well y’know!

    Rudolph the red-dusted Strömgren sphere
    Was a very gassy ball
    And if you ever saw it,
    You would even say it glows

    At least in the infra-red
    As this WISE shot shows
    Rudolph with your gassy glow
    We’ll call you Barnard Three that’s so!

    All of the other nebulae
    Often also had Barnard names
    But they never let poor Rudolph
    Join the intergalactic games

    Then one distant Xmas eve
    On far off planet Earth
    The WISE shot showed Rudolph so bright
    Barnard Three what an awesome sight!

    Then all the nebulae loved him
    Said “You can be an APoD* too!”
    Rudolph the red-dusted Strömgren sphere
    For Christmas Eve we think you’ll do!


    Yeah, I know I’ve had to mess around ith the verse order just a trifle. Still best I could come up with in the appropriate doggrel dept. :-)

    * APod = Astronomy Picture of the Day – click on my name for the site. Alas, B3 is not yet there that I could find.

  12. PS. Oops forgot you guys are a day behind us here in Australia for a second too. Oh well still sorta works I hope.

    Hmm … There does seem a slight shortage of the dark Barnard nebulae on APoD – still no luck finding it there. Only 3 the Horsehead, Barnard 72 or the Snake nebula and Barnard 68 appear on their index – although Barnard 163 appears elsewhere in the search. Oh well, guess I can hope they add this one tomorrow then! 😉

  13. Marina

    You see a reindeer? I see a five-pointed star. In a circle. With a ruby in the middle.

  14. Bartman

    So this isn’t related to Beta Stromgren?
    Too bad, since that star is gonna go Supernova in 2366

    Yeah, yeah, I know, but I couldn’t resist.
    I liked the series, but not a geek.
    I only remembered the name because I thought the name Beta Stromgren was pretty cool!


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