What youâre seeing is the Tarantula Nebula, an unimaginably huge star-forming gas cloud. Itâs located in the Large Magellanic Cloud, a satellite galaxy to the Milky Way, about 170,000 light years away (as usual, you can grab a bigger shot, or even a ridiculously huge 16,600 x 15,000 pixel version). The picture looks a bit odd to me, but thatâs because itâs a mix of visible and infrared light. This strongly accentuates gas and dust, and gives the nebula that overall pinkish color in the picture. (Iâve written about this nebula many times; see Related Posts below for more eye and brain candy.)
The Tarantula is one of the largest star-birth factories known, busily churning out hundreds of thousands of stars. Most nebulae produce stars in far smaller numbers. The Tarantula is so fecund, in fact, that astronomers think it may actually be creating a globular cluster, a massive spherical collection of stars. Most of these are very old (like billions of years old), so being able to see one in the process of formation is a real boon.
Thereâs so much to see in that image! Let me point out a few highlights.
First, right at the brightest part of the nebula (left of center in the big picture, detailed above) you can see a clump of stars. Thatâs R136, the main cluster of stars in the nebula. Several of the stars in it are huge, about 100 times the mass of the Sun. Stars get hotter the more massive they are, and those stars are so big theyâre on the edge of tearing themselves apart. The cluster provides most of the energy lighting up this gas cloud, which is pretty impressive given that the Tarantula is 650 light years across!
In the main image, see the two curves at the bottom, like a stretched-out W? Those are the edges of gigantic cavities in the cloud, carved out by the fierce light from the stars in R136. It eats into the gas and dust, eroding it, leaving those weird shapes like fingers and sandbars in a stream. In fact, when you zoom in, you can see more evidence of this:
That finger of gas on the left points directly at the cluster (âupstreamâ) and is whatâs left after the erosion. Thereâs probably a denser knot of material at the tip, which has protected the material âdownstream.â Sometimes thatâs where stars are born, though in the powerful and deadly environment of the Tarantula, itâs possible all the gas will be stripped away before any stars can properly get going.
The carving out of bubbles is happening on smaller scales, too; to the far right in the main photo is this little guy:
You can see a small bubble on the right, almost certainly being blown by the winds and light of the stars forming inside it. That looks to me like a decent-sized gas cloudâ20â30 light years across or soâbut itâs positively dwarfed by the magnificence to the left. That seems unfair, but the Universe doesnât really care about artistic justice.
R136 is not the only cluster of stars in the nebula. To the upper left in the main photo is another tight collection of stars, called Hodge 301:
As you can see, there doesnât seem to be much gas and dust around the cluster; itâs probably been cleared out by the stars within. Not only that, but Hodge 301 is somewhat older than R136 (probably 20 million years or so) which means many of its stars have already exploded, gone supernova, which has no doubt helped blow away material around the site.
Thatâs just a taste of whatâs going on here. Thereâs much more to see, and I leave it to you to scan the high-res image and discover what lies inside. It probably wonât surprise you to learn that many astronomers have devoted their entire careers to studying this massive and rich nebula. Looking over this picture, itâs easy to think there are far worse ways to spend your life.
All photos by NASA, ESA, E. Sabbi (STScI)