Baby stars blasting out jets of matter

The entire universe in blog form
March 16 2011 6:00 AM

Baby stars blasting out jets of matter

I know I've been posting a lot of astropr0n lately, but there's just been so much cool stuff the past few days (and there's more to come)! The European Space Agency just threw their hat into the ring with this crazy cool image of a young star blowing its stack:

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

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I love this image! It shows the havoc caused by young stars as they spew out material at speed upwards of a million kilometers per hour. What you're seeing is actually a small part of a star-forming region surrounding the star R Corona Australis, a nearby 550 light years away. It's a densely packed cloud of thick dust and gas, completely hiding the stars inside and behind it. It's not terribly big, only a couple of light years across -- compare that to the Orion Nebula, which is 20 light years across (and that's only the visible portion; it's part of a dark cloud that's much larger). Or the Tarantula nebula, which I posted about yesterday, which is a thousand light years across!

Even though it's small, it's the birthplace of many stars. Two such stars reveal their presence here; not by their light, but by blowing out long streamers of matter called jets. Technically, they're called Herbig Haro objects (I have an explanation of these objects in an earlier post, which also has a stunningly lovely picture). One of them is the bright series of bow shocks leading right down to that brightly glowing blob of gas at the bottom of the picture. The curved waves are usually caused by episodic spasms from the star, expelling gusts of wind which interact with previously blown-out material. The long, bright streamer to the left of the jet is probably material compressed by the jet as it expands. It's not actually part of the jet itself, and shines by reflected starlight.

That blob at the bottom is very interesting. It's probably where the jet from the star has plowed into so much material that it's slowed down radically, and vast amounts of matter have piled up in front like snow in a snowplow. The gas in there must be violently turbulent, and you can see the filaments of gas flowing around it.

The second jet is harder to see, but it's on the right, and can be seen as a series of short vertical arcs that are blue and red. The star blasting that jet out is well off to the upper left of this picture.

Last year, the ESO released a wider-angle view of this region:

You can see the comma-shaped material near the center here, as well as the bright terminus blob of the jet at the bottom... but the jets are essentially invisible. That's because the picture up top was taken using filters which accentuates the glow from hydrogen and sulfur gas (common in Herbig Haro outflows), but the wider image is more true-color. Only very bright gas shows up well.

Although this region is small, it's making several dozen stars, a dozen of which at least are Herbig Haro objects. Their jets slam into the surrounding gas, really making a mess of it. Seeing something like this, it's hard not to wonder what the local scene looked like when the Sun was born. Did the elements which make up our bodies, our planet, our star, coalesce in a small cloud like this, or a giant factory like the Tarantula or Orion? Some dense clouds form only one or two stars, and we may have come from one of those! Only by studying these gorgeous objects will we ever know the answer that.

I think it's cool we can even ask that question, but it's truly fantastic that we can actually expect to figure out the answer.

Image credit: ESO