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. (more…)
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: (more…)
[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.
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…
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
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