I am continually amazed at what the huge infrared space-based observatory JWST can do. I mean, I know its capabilities, and I know it has a huge mirror and fantastic ability to detect faint objects and see in incredible detail. I worked on Hubble long enough to know what these beasts can do! But then I read a paper about an observation that is both fantastically spectacular as well as scientifically crucial, and my socks are once again blown right off my feet. 

Seriously. LOOK AT THIS.

HOLY WHAT.

This is one of the most jaw-droppingly mind stomping images I’ve seen from JWST. Wow. And there are much, much larger version available for download at the ESA JWST site.

That is NGC 602, a very young nebula — a cloud of gas and dust — in the Small Magellanic Cloud (or SMC), a tiny satellite galaxy to our much larger Milky Way. The SMC is about 200,000 light-years away from us, visible by eye from the southern hemisphere. 

NGC 602 is very actively forming stars. It has enough material to make about 1,500 stars like the Sun, and you can see the newborn cluster of them to the left of center.

In this case about a dozen of these stellar infants are very massive O and B stars, the most luminous kinds nature can create [link to journal paper]. Stars like this blast out intense amounts of ultraviolet light, which is a higher-energy form of light than we can see with our eyes. These photons slam into the material around the stars and literally break up the molecules, a process called photodissociation. Over time the light eats away at the material, forming a huge cavity around the cluster, which is pretty obvious in the image.

The speed at which material dissolves under that onslaught depends on its density, how much of it there is packed into a particular space. Denser knots of matter take longer to get blown away, so what happens is they form long, skinny fingers as material off the starward-facing side of the clump dissolves and is blown backwards (just like in the famous “Pillars of Creation” shot). It’s very similar to water flowing around a rock in a stream, forming a parabolic sandbar. You can see dozens of these structures all around the cluster; note how they all point right at the cluster stars because that’s “upstream”.

Just like in visible light, in infrared different kinds of material emit light at different wavelengths (or as you might think of them, colors). The important one here is the yellow; that’s a wavelength of 3.35 microns (about 5 times the wavelength of the reddest light you can see by eye) and is primarily emitted by long chains of carbon-based molecules called — and I love this because fancy words appeal to me — polycyclic aromatic hydrocarbons, or PAHs. Weirdly, they’re basically soot! Astronomers also generically call this material dust, and it’s made when massive stars start to die and expand into red supergiants. They have a lot of carbon in their outer layers, which then blows out into space and creates the PAHs. This material can be quite dense in cosmic terms, and that’s where we see those long fingers of denser material.

New stars are being born in the clumps at the tips of those fingers. You’re seeing the stellar birth process laid out in front of you, 2 quintillion kilometers away.

Oh, but there’s more.

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