In the heart of the Large Magellanic Cloud (one of the Milky Way’s many satellite galaxies), there lies a vast complex of gas called 30 Doradus. And inside that sprawling volume of space is the Tarantula Nebula, a star-forming region so huge it dwarfs even our own Orion Nebula. Thousands of stars are churning away in there, going through the process of being born.
And as they do, the hottest and brightest of them carve huge cavities in the nebula, heating the tenuous gas therein to millions of degrees. The result? This:
[Click to embiggen.]
I love this image! It’s a combination of observations from the Chandra X-Ray Observatory (in blue, showing the incredibly hot gas) and from Spitzer Space Telescope (in red, showing cooler gas). Those bubbles of hot, X-ray emitting gas are constrained by the cooler gas around them, but it’s likely the hot gas is expanding, driving the overall expansion of the nebula itself. However, it’s also possible the sheer flood of high-energy radiation from the nascent stars is behind the gas’s expansion… or it’s a combination of both. Astronomers are still arguing over this, and observations like this one will help figure out who’s right.
… but you know me. I love pareidolia, and there’s no way you can look at this image and not see a really angry screaming face, shrieking at that blue blob hovering in its way. That’s so cool!
And c’mon, NASA: you release this image two weeks after Halloween? Oh well, I’ll add it to my scary astronomy gallery anyway, which is after the jump below.
Image credit: X-ray: NASA/CXC/PSU/L.Townsley et al.; Infrared: NASA/JPL/PSU/L.Townsley et al.
I’ve been an astronomer a long, long time. Even so, I still sometimes get surprised at how different the same object can look when imaged in different ways. I just saw an excellent example of this… W5, aka the Soul Nebula:
[Click to ennebulanate.]
Pretty, isn’t it? It was taken by César Cantú, an amateur astronomer in Mexico. It’s not a true color picture. Not even close! For one thing, he used three filters which let through extremely narrow wavelengths of light (that is, the filters reject all light except for a very thin range of wavelengths; I’ve written about them before). Our eyes see broad ranges of colors, so immediately these filters change the very nature of the picture. Different atoms in space emit at different colors, and the filters he chose select for hydrogen, oxygen, and sulfur, which tend to emit light very strongly in gas clouds.
Not only that, he mixed and matched the colors. The hydrogen filter lets through red light, but he colored it green in the picture; oxygen is usually green but he made it blue*; and sulfur is red which he actually did color red. This throws off my usual sense of what I’m seeing in a picture (I really am used to hydrogen being red and oxygen green) so it forces me to re-evaluate how I see this gas cloud.
Spitzer Space Telescope is an orbiting infrared observatory. It ran out of coolant a few years back — needed to keep its highly sensitive IR cameras working — but before it did, it took this amazing image of a young star blasting out twin jets of matter:
Neat! [Click to collimatenate.]
The star is called Herbig Haro 34, and is only a few million years old. Stars that young rotate rapidly, have fierce magnetic fields, and thick disks of material surrounding them (out of which planets might form). All these things together help focus twin beams of matter called jets, which blast away at high velocity from the star’s poles. We see these quite often around young stars.
But the jets blowing off of HH 34 are weird. They aren’t symmetric.
Astronomers figured they should be. Sometimes the jets blow out knots of gas or sputter a little. And when that happens, whatever forces acting on the star and disk should act on both jets at the same time. But that’s not the case for HH 34: the jet on the right does the same thing the jet on the left does, but only after a 4.5 year delay!
Figuring this out at all wasn’t possible until this Spitzer image was taken. Before, visible light images only showed one jet:
Things I love: astronomy, geeks, dorky humor, the scientific method.
And hey, Veronica pronounces Uranus correctly! She’s awesome.
If you like that video, then check out some of the others they’ve made with Friends of Bad Astronomy™:
[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.]
One of the things NASA takes seriously is the goal of educating people about astronomy. Happily, while everyone takes the goal seriously, they’re not necessarily serious about how to achieve that goal…
Enter IRrelevant Astronomy: a series of educational videos about astronomy, leaning on the infrared aspects of it (because it’s created by folks with the Spitzer Space Telescope, which sees in the IR). These aren’t the bland, dull videos of yesteryear! The videos in this series are really, really funny — I mean laugh-out-loud funny — and frequently feature celebrities like Felicia Day and Sean Astin.
They just released a new one, "Destroyer of Worlds", and I bet you just might recognize the voice of The Physician…
There were many times I was laughing at this video. And not just at Wil Wheaton’s voice acting (though he’s really good at this). It’s got that perfect Warner Brothers cartoon zeitgeist: kids will like the zaniness, and the adults will get the jokes. I’m not sure if my favorite part is the insect-like spaceship near and dear to my heart seen several times, or The Physician’s ship itself. Either way, this is one of the best of the Spitzer videos. And the science, including binary stars disrupting their planets’ orbits, is pretty interesting and handled quite well.
Tip o’ the sonic screwdriver to Wil for blogging about this (and the link lurv).
More exoplanet news, and yet another instance where the more we look at them, the weirder they get.
Spitzer Space Telescope sees in the infrared, so in a way it can measure the heat from an object. The orbiting observatory was pointed at the star Upsilon Andromedae, one of the very first stars known to have exoplanets. One of those planets, Ups And b, orbits so close to the star that it makes a complete circle around it every 4.6 days.
That close to the star, the planet should be tidally locked: one side always facing the star, and very hot; the other facing away, and much cooler. As the planet goes around the star, from our vantage point we see first the hot face, then the cooler one, and back again, a cycle repeated every 4.6 Earth days.
Now, we can’t separate the planet from the star; it’s way too close for that. But the planet gives away its presence by the hot and cool faces. We expect to see the hot face when the planet is on the far side of the star from us: it’s then we see the lit, hot face of the planet pointed toward us (the orbit is tilted enough that the star doesn’t get in the way). That hot face gives off infrared light, which adds a tiny bit of infrared light to the total we see from the system. 2.3 days later, the back side of the planet is presented to us. It’s cooler, gives off less infrared, and we see a dip in that light.
By measuring the amount of light, and when we see it, we can infer quite a bit about the planet, like how hot it really is. But astronomers got a surprise…
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.
The folks at Spitzer Space Telescope recently released a new image, and it’s a stunner:
Wow, what beauty! This picture shows the famous Orion nebula, one of the galaxy’s largest and most active star forming gas clouds. Spitzer is an infrared telescope, so blue here depicts light at 3.6 microns, roughly 5 times the wavelength your eye can see, and red/orange is 4.5 microns.
I could go on and on about the ethereal beauty of this image, about how we can actually see stars forming here, about why there are streamers and shock waves that sculpt this vast light-years long structure. But you can find me expositing at length on all those topics in other posts about other nebulae. That’s not the point I want to make here.
When I first saw the image, the email from JPL had the subject line "Colony of Young Stars Shines in New Spitzer Image", so I didn’t know what nebula it was showing. I simply clicked the link, and the image above popped up. I smiled when I saw it because of its beauty, at least at first. But after a moment I was puzzled. The nebula looked familiar, but for a brief moment I couldn’t place it. Then I focused my attention on the big cloud on the left, and my mind snapped into clarity.
Any amateur astronomer on this planet can identify the picture at the left in a heartbeat. That’s an optical picture of the Orion nebula, one taken using visible light (the picture is by Hubble; click it to get more info and access to much, much larger versions). I’ve rotated the picture to match the one from Spitzer; you can see the same curved shock front going across the lower left corner, and the round comma-shaped cloud with a star near its center to the right. While the Hubble image is far more detailed (and colorful!) than what you see through an eyepiece, it still strongly resembles the view through a good telescope. But the Spitzer image…?
Have you ever met up unexpectedly with a friend you haven’t seen in five years? Maybe they grew a beard, or lost weight, or dyed their hair, or changed their clothing style. It’s the same person, clearly, but somehow different. It takes a second to recognize them, and when you do, it’s a bit of a jolt.
That’s exactly how I felt when I saw the Spitzer image (and like many an astronomer, I consider Orion an old friend). Spitzer’s image is just a little bit into the infrared, enough that details are different while the overall shape and features are the same. I knew it was my old friend, but it took me a moment to recognize its face.
And in many ways, like seeing that acquaintance after a few years, there were new things to learn, new ways to experience our friendship. The stars in the Spitzer image that are in the narrow bridge between the two halves of the nebula seem a bit more vibrant, a bit more obvious… as they should, since they are young stars in the throes of birth, and veiled substantially by dust. More stars overall are apparent in the image, since fainter ones can shine through the dust in the infrared, while their light is blocked by that dust in the visible. The streamers in the infrared image are more vivid, but the dust features less so, again as expected, but still somehow new and interesting.
In my travels I do happen to run across friends I haven’t seen in many years, and when I have time to actually sit and chat, I’m delighted when they have grown and done things they have previously not experienced. It brings a new side of them to light for me, lets me see them in a new way and appreciate them all the more.
And this is true on Earth as it is in the heavens. There are so many things to see in and above this world, and so many ways to see them! New eyes, new perspectives, new ways of seeing… it makes me always eager to find out what’s next, and to cherish what we already know.
Every now and again I think I’ve pretty much seen it all when it comes to astronomical images, and I’m getting jaded.
And then I see a picture like this:
Yeah, I still get a thrill from seeing things like this! Click to massively embiggen.
The image shows what’s called the Hickson Compact Group 31, a small collection of galaxies. It’s a combination of images from Hubble (visible light, shown in red, green, and blue), Spitzer (infrared, shown as orange), and the Galaxy Explorer or GALEX (ultraviolet, seen here as purple).
If I saw this picture with no caption, I’d know I was seeing dwarf galaxies colliding; the shape and the glow from newly-forming stars is a dead giveaway. But I’d also guess that the galaxies were young; old galaxies tend not to have much gas in them, and there’s clearly plenty of that in those galaxies! But in fact the galaxies here are very old; there are globular clusters (spherical collections of perhaps a million stars each that tend to orbit outside of galaxies) in the group that can be dated to being 10 or so billion years old. That means these are old objects, reinvigorated by their collision.
In fact, star clusters inside the galaxies can be dated as well, and appear to be only a few million years old. Oddly, the gas content of the galaxies is very high, with about five times as much as the Milky Way has. That’s pretty weird; it should’ve been used up a long time ago. Apparently, these galaxies have lived very sedate lives until very recently. I’ll note that they are relatively close to us, about 166 million light years away. Usually, colliding dwarf galaxies like this are seen billions of light years away, so we really are seeing them as they appeared recently.
Apparently, the lower-case g-shaped object on the left is the result of two galaxies smashing into each other, and the longer galaxy above them is separate. The spiral to the right is part of this as well and may be involved in the gravitational dance; you can see a splotchy arm of material pointing right at it from the collision on the left. Typically in collisions the gravity of one galaxy draws matter out of the other, and that can collapse to form stars. The red glow is from gas excited by newly born stars, and the blue glow is from these stars themselves. The galaxies are pouring out ultraviolet light (the purple glow) which is another dead giveaway of vigorous star formation.
The background galaxies are gorgeous, too. There’s a phenomenal distant open spiral on the bottom, to the left of center, and what looks like yet another pair of interacting galaxies at the bottom left, obviously much farther away than the Hickson group. Take a minute to look around the high-res version to see what else you might find!
Yup. I guess you can teach old galaxies new tricks… and even sometimes jaded astronomers, too.