When a human is a baby, it has a mass of a few kilos and eats milk.
When a star is a baby, it has a mass of an octillion tons and eats sandwiches a trillion kilometers across.
Don’t believe me? Well good, because I’m being a little metaphorical. But still, this newly released Hubble image backs me up:
[This is a gallery of gorgeous images, my favorites, from the orbiting infrared observatory called the Spitzer Space Telescope. Click the thumbnail picture to get a bigger picture and more information, click the big pictures to go to my original blog posts about the pictures, and scroll through the gallery using the left and right arrows.]
A few years back, astronomers discovered that some distant galaxies were blasting out vast amounts of infrared light, but were very faint in visible light, the kind we see. They termed these objects ULIRGs ("you-lurgs"), for Ultra Luminous Infrared Galaxies. The idea is that these galaxies are forming lots of stars, but there was so much dust choking the region that all the visible light was blocked. However, infrared light can pierce through the dust, so telescopes that detect IR can see them. Due to the physics of the situation, astronomers also figured there must be two populations of these galaxies; the ones they had found, and another that was (very) slightly warmer.
I know, they don’t look like much, do they? But you have to realize what you’re seeing here: those circled blobs of light are entire galaxies, with billions of stars, and they’re a staggering 11 billion light years away.
That’s really, really far. The Universe is only 13.7 billion years old, so we’re seeing these galaxies as they were just a few billion years after the entire Universe came into being. Not only that, but the amount of infrared light these galaxies are emitting is truly terrifying: in the infrared alone, they are blasting out a solid trillion times the Sun’s entire energy output.
A trillion! 1,000,000,000,000! That’s a whole lot of energy. And it comes from a whole lot of newborn stars, because these galaxies are cranking out stars at a rate 700 times that of our own Milky Way galaxy! The view inside those galaxies must be breathtaking; imagine being surrounded by the Orion Nebula everywhere you look. Wow.
What cracks me up about this too, is how they found them. The European Space Agency is using the orbiting Herschel Infrared Observatory to take a survey of galaxies in the IR. It’s finding a lot of them; in the picture above every dot you see is an infrared source, most likely a galaxy. And that’s a small section of the sky; on the right is an image of a bigger part of the survey. You need to click it and see it full-res to get a sense of how many freaking galaxies there are out there!
As far as astronomical discoveries go, this is another in a long series of steps needed to understand the Universe. I know that in your daily life this may not affect you much; you have other things on your mind, daily stresses and such. But you know what? While I go about my everyday business, in my mind I’m occupied by all the mundane and gross worries of life just like you are, just like everyone else is. But somewhere back there, in some part of my brain, there is knowledge that sits there… and every now and again, it makes itself known.
We can see galaxies a hundred billion trillion kilometers away! We know that stars are being born there, stars like the Sun, and they’re being born every day! If you were there, the sky would be a riot of red and green gas strewn in sheets and ribbons and shock waves and festooned with brilliant jewel-like stars everywhere you looked!
Those wonders are out there, and they’re real. That makes my life better, just knowing that.
Image credit: ESA/SPIRE/HerMES
Astronomers using the UK’s Infrared Telescope (UKIRT) have made an important discovery: massive stars form much like lower mass stars do.
That doesn’t seem surprising, does it? Ah, but it is. It turns out that massive stars are different than the hoi polloi like the Sun, and it’s a bit puzzling that they can form at all!
As I’ve written many times before, stars form from clouds of gas and dust. A cloud can be huge, light years across, its massive gravity balanced by internal heat. But collisions between clouds or nearby exploding stars can disturb that equilibrium, compressing the cloud. Random eddies and whorls in the cloud can be accelerated, amplified by the collapse, giving the entire complex an overall rotation. Random collisions between pockets of matter inside the cloud slowly rob them of energy, causing them to move inward, falling toward the cloud’s equator. What was once a giant amorphous mass is now a relatively rapidly spinning disk of material.
Deep inside the Milky Way’s companion galaxy called the Large Magellanic Cloud lies a vast complex of stars, gas, and dust. From our vantage point, 170,000 light years away, we see it as a softly-glowing pinkish brain-shaped cloud studded with stars — a description that grossly underdescribes the tremendous beauty of the newly-released Hubble view of it:
Oh, my. Click it to get a bigger version, or go here to get a 26 Mb 4000×4000 pixel version.
What a staggeringly lovely image! And so much to see. More than you’d expect… but that’s part of a surprise I’ll have for you at the end of this post. Bear with me, it’s worth it.
Until then, let me show you a thing or two…
Great beauty in art, it is sometimes thought, comes at the price of great strife. Massive forces, both internal and external, shape the flow of artistry. This metaphor applies equally well to galaxies as it does to humans.
Of course, when the Universe is your canvas, the scale’s a little bigger. Like with this dramatic Hubble view of the spiral galaxy M66:
[Oh yes, you most assuredly want to click that to see the galactic 3906 x 2702 pixel version.]
Mmmmm, pretty. Artistically, I like this shot in particular because of the angle and the way it’s framed; when I look at it I get the impression that it’s looming over me, and I perceive it to be sliding by. The sense of motion frozen in time is palpable.
But then the nerdy science part of my brain kicks in; numbers and physics fill in the back story of the artistry, making the picture even cooler than it looks. That galaxy is as big as the Milky Way: 100,000 light years across. It’s 35 million light years away — 350 quintillion kilometers, more than 200 quintillion miles. It’s also part of a trio of galaxies, the other two being M65 and NGC 3628 — the Leo Triplet. When I was younger, I used to observe them through my telescope in late spring when Leo the Lion was high in the sky to the southwest. They weren’t much more than smudges, but my already-getting-ready-to-be-a-scientist brain knew that I was seeing trillions of stars, dimmed by their unfathomable distance.
I was out of town at a wedding this weekend, so I missed blogging about the spectacular image release for the Hubble Space Telescope’s 20th anniversary (here’s the US site). And yikes, it’s simply mind-smackingly mind smacking. Behold:
Ye gods. Click to get access to massively embiggened versions.
This is a stunning close-up of a section of the vast Carina Nebula, a sprawling and complex Escher-like region of gas and dust about 7500 light years away. It’s the scene of chaotic star birth and death, slammed and reslammed by winds from stars being born and others busy blowing up.
Ever since the Hubble upgrade a few months ago I’ve been waiting to see the results of it getting back to routine science observations… especially for the new Wide Field Camera 3, which promised to return gorgeous imagery.
Well, the wait’s over. The first image is out, and it’s a nice one: star formation in the spiral arm nurseries of the nearby galaxy M83:
[You know the deal: click it to embiggen, or go here to grab a delicious 15 Mb 3900×3900 pixel version.]
M83 is about 15 million light years away, making it practically a next door neighbor for the Milky Way, as well as a tempting target for telescopes. Proximity = clarity in most cases, and with M83 we have a great view of its lovely spiral arms. This new image from Hubble’s WFC3 shows unprecedented detail, too. There are star clusters everywhere, factories cranking out baby stars by the millions. There are also something like 60 supernova remnants, the expanding gaseous debris from exploded stars, five times the number previously seen in this galaxy.
The colors are interesting. This picture is not quite true color. Sure, blue is blue, green is green, and red is red, but they also added a second version of red coming from the light of warm hydrogen gas (called Hα in astronomical parlance) as well as a fifth color: cyan (turquoise) coming from the light of warm, tenuous oxygen. That light is typically emitted from gas clouds making stars as well as the gas emitted from stars when they die (in fact, my PhD thesis was based on observations of this oxygen-light glowing from a ring of gas around an exploded star). You can see that this teal-like glow pervades the entire image: oxygen is everywhere! But it’s so thin it’s more like a hard laboratory vacuum than anything you could breathe.
Also, if you look closely at the pockets of red clumpy gas, you can some that are edge-brightened, like a soap bubble. These are where stars are being born in vast numbers. Their mighty winds expand outwards, carving huge cavities in the gas. My favorite is the one in the middle left of the image, zoomed in here for your viewing awesomeness. The stars are so closely packed they blur together, and each that you can see here would dwarf the Sun in mass, size, and brightness. You can also see that the rim of the bubble is more pronounced below the star cluster, which means that the surrounding gas in the environment of the cluster is thicker there, and has piled up more as the expanding winds have snowplowed it.
And everywhere in this picture are the dark ribbons and filaments of dust, dust, dust. These are long molecules (usually with lots of carbon) which are created by new stars and dying stars. They litter galaxies like M83 as well as our own. And while they make life difficult for optical astronomers who struggle to penetrate the thick veil and see what lies beneath, the dust is interesting all by itself… and adds a certain depth and grace to images like this one.
And, on the right of the big image, is the white glow of the galaxy’s nucleus. You can see detail of the dust, stars, and gas all the way down to the very center. It’s an amazing image, and I’m sure will keep astronomers busy for a long, long time.
What a great start to the return of the Hubble! And, as always, I can’t wait to see what’s next.