One of the basic principles of modern science is that the physics we understand here, on Earth, work everywhere. This turns out to be a pretty good assumption, because we see it coming true time and again. That knowledge can then be used to figure out things that are happening at very large distances — even well across the Universe.

With that in mind, I present to you LAB-1: a glowing glob of gas as seen by the European Southern Observatory’s Very Large Telescope:

[Click to, um, englobenate.]

This, however, is no ordinary Space Blob: it’s located at the staggering distance of 11.5 billion light years from Earth! Not very many objects have been seen farther away than this, and it’s one of the single biggest discrete structures seen this far away. It’s about 300,000 light years across — three quintillion kilometers, or three times the diameter of our own galaxy. That’s pretty flipping big.

And although it’s faint to our telescopes, at that distance it must actually be tremendously luminous for us to see it at all. Something is making it glow fiercely, but what? One hint is in the cloud’s name: the LAB in LAB-1 stands for Lyman Alpha Blob. Lyman Alpha (written as Lyman-α) is a specific color of light you get from hot hydrogen gas (just so’s you know, it’s emitted when the electron in a hydrogen atom jumps down from the second to the lowest orbital energy state). Normally, Lyman-α is in the ultraviolet, but this blob is so far away the light is shifted by the expanding Universe into the optical region — that’s why it looks green in the image above.

It takes a goodly amount of energy to create Lyman-α light, so something big is going on here. Maybe this gas cloud is collapsing under its own gravity, and is heated up. Or maybe there are big galaxies inside of it, causing it to glow. How can we tell which is the culprit?

It turns out there is a way: polarization.

(more…)

[Update: I originally had called this the Very Large Survey Telescope, but have learned it's actually the VLT (for Very Large Telescope) Survey Telescope. I've corrected this in the title and below. I like my less-redundant name for it better, but it's best to be accurate.]

The European Southern Observatory is an agency that governs some of the best telescopes on the planet, and they just added a new eye on the sky: the VLTe Survey Telescope (VST), a 2.6 meter ‘scope in Chile. There are lots of telescopes of similar size dotting our planet, but what makes this one special is its huge field of view — a solid one degree across, twice the diameter of the Moon on the sky – and the resolution of the camera: a terrifying 268 megapixels!

When you put that together, you get some dazzling pictures, like this one of the globular cluster Omega Centauri:

[Click to englobulenate to a 4000 x 4000 pixel 13 MB image, or grab yourself the internet-choking 14,540 x 14,540 pixel 280 MB version.]

Omega Cen is one of the largest globular clusters of the 150 or so orbiting the Milky Way galaxy, a collection of hundreds of thousands or even millions of stars all orbiting the cluster center willy-nilly like bees swarming around a hive. Telescopes like the VST will allow astronomers to survey these clusters quickly and deeply, which is important because it’s sometimes difficult to know what stars are in the cluster and which happen to be in the background or foreground. You have to get a good census of cluster membership before moving on to studying how old the stars are, what they’re made of, and how they behave. Since globulars are among the oldest objects in the Universe and are tied with galaxy formation, understanding them leads to understanding a great deal more.

VST also took this spectacular picture of the star-forming region M17, also known as the Omega nebula:

(more…)

The Carina nebula is a sprawling, monstrous complex of gas located a mere 7500 light years from Earth. Hundreds of light years across, it’s massive enough to create thousands of stars like the Sun. Tens of thousands.

And churn out stars it does. Embedded in the nebula are several clusters of newborn stars, and many of these stars are so massive they’re nearly at the limit of how big a star can be without tearing itself apart. Stars that big explode as supernovae, and a new mosaic by the orbiting Chandra X-ray Observatory indicate they’ve been popping off in the nebula for quite some time:

[Click to enchandrasekharlimitenate.]

This image is pretty amazing: it’s a mosaic of 22 separate images by Chandra, covering 1.4 square degrees (seven times the area of the full Moon on the sky), and represents an exposure time of 1.2 million seconds! Since it shows X-rays coming from astronomical objects, it’s false color: red is from lower energy X-rays, green is medium energy, and blue from the highest energy photons.

The diffuse glow is from two sources: the stellar winds from those massive stars slamming into surrounding ambient gas at high speed, and from the shock waves generated when supernovae explode. Both are extremely high-energy events, and produce copious amounts of X-rays. That long, horizontal arc is probably the edge of a bubble, a shell of gas piled up from the winds of stars and supernovae like snow piled up in front of a snowplow.

That’s evidence right there that Carina has been cranking out supernovae over the past few million years. Interestingly, it’s what’s missing that provides more proof. (more…)

Orion is a morning constellation right now, high in the sky if you get up early enough. The three stars making the belt are obvious enough, and just below it hangs his dagger^*. The middle star in the dagger is not a star, but a star-making gas cloud of mind-numbing size. There is much to see in the vast sprawl of its 5000 cubic light year volume, including young stars, still going through the pangs of birth.

One of these is the strange object called Herbig-Haro 502: a newly-born star shooting twin jets of material, far, far out into the nebula itself. Its beauty is simply breathtaking, as you can see in this spectacular image from Hubble:

[Click to ennebulanate to the giant 3800 x 3800 pixel version.]

Against the background gas of the Orion Nebula, HH 502, as those of us in the know call it, is almost lost — it’s the star just to the left of center wrapped in what looks like pink gauze (the jets are easier to spot in the full-res version). This image is a tiny, tiny fraction of the entire nebula, but the detail is exquisite. You can trace the jets of gas quite a ways. In real terms, the whole object is roughly a light year — 10 trillion km, 6 trillion miles — end to end. Neptune’s orbit would be a razor thin slice of a pixel on this scale.

There’s a lot to see. If you look carefully, you can see arc-shaped features all over the place. These are bow shocks, like the shock wave off the nose of a plane moving faster than sound. That’s usually caused by winds of gas screaming off of stars and slamming into the gas around it. Really elongated ones can be seen, too, and those are associated with the material firing away from the star at HH 502′s center.

(more…)

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…
(more…)