Tag: filaments

The cold, thin, glorious line of star birth

By Phil Plait | April 14, 2011 7:00 am

At the end of May, 2010, the European Space Agency’s orbiting Herschel telescope was pointed toward a dark cloud in space over 2500 light years away. What it saw may solve a bit of a scientific mystery… and is also truly beautiful:

[Click to ennebulanate.]

This object is called IC5146, and consists of the Cocoon nebula on the left, and two long streamers of gas extending to the right. Herschel is very sensitive to cold dust in the very far infrared; in this image blue shows gas and dust emitting at a wavelength of 70 microns (the reddest color the human eye can see is roughly 0.7 microns), green is 250 microns, and red 500 microns — that’s over 700 times the longest wavelength light the eye can detect.

The Cocoon nebula is a well-known gas cloud being lit up by a massive, hot star in its center. In the visible light image inset here — grab the stunning high-res version to compare to the Herschel shot — the dust is dark, since it absorbs the kind of light we see. Also, stars are pretty faint at these extreme infrared wavelengths, so they don’t interfere with the observations of the gas and dust. That’s why observatories like Herschel are so important: they allow us to investigate objects that might be invisible to other telescopes.

As you can see in the Herschel image, the entire region is interlaced with long, thin filaments of dust. This dust is cold: much of it is only about 15° Celsius above absolute zero, or -430°F! What’s so very interesting is that the filaments, no matter what length they are (and as seen in other parts of the sky by Herschel as well), seem to have about the same width of roughly 0.3 light years across. That argues very strongly that these filaments are formed from turbulence in the dust, probably caused by exploding stars roiling up the matter between stars. That width is just about what you’d expect as shock waves from exploding stars slam into each other, interact, and become turbulent.

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The boiling, erupting Sun

By Phil Plait | October 28, 2010 7:00 am

I keep thinking there’s nothing new under the Sun– or on it. With SOHO, and SDO, and a thousand other telescopes pointed at it, it would take something pretty freaking cool to surprise me.

Well then. Surprise!


Holy solar retinopathy! That’s the Sun?

Yup. But this is not a space-based image from some bazillion dollar observatory! This phenomenal picture was taken by astrophotographer Alan Friedman with this relatively small (but very, very nice) ‘scope. He shot it on October 20th, and it shows our nearest star in the light of hydrogen, specifically what astronomers call Hα (H-alpha). I’ll get to that in a sec…

In this picture you can see sunspots, giant convection cells, and the gas that follows magnetic loops piercing the Sun’s surface. When we see them against the Sun’s surface they’re called filaments, and when they arc against the background sky on the edge of the Sun’s disk they’re called prominences.

The image he took is amazingly high-resolution! He has two closeups, one of the filament and sunspot near the edge of the disk on the left, and the other of prominences leaping up off the edge and silhouetted against the sky:

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CATEGORIZED UNDER: Astronomy, illusion, Pretty pictures

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