After I posted the video of the solar eruption earlier this week, I got a lot of questions about why material fell back from the explosion onto the Sun. The quick answer: gravity! A lot of the material from a prominence like that falls back onto the Sun because of the Sun’s strong gravity. Since the material is an ionized plasma – a gas stripped of one or more electrons — it follows the magnetic field lines of the Sun, so you can see graceful arcs of this stuff falling back down after the blast (see Related Posts below for links to more detailed descriptions of this phenomenon).
Oh, why describe it when I can show you? This video is from the NASA/JAXA Hinode spacecraft which observes X-rays from the Sun. It caught the event in loving detail:
See? Gravity does the work, but magnetism does the steering.
Tip o’ the phased plasma rifle in the 40 Watt range to Camilla Corona SDO.
– GORGEOUS solar eruption!
– Desktop Project Part 8: From filament to prominence
– The Sun decided to blow off a little steam today. Twice.
– Gorgeous flowing plasma fountain erupts from the Sun
– A fiery angel erupts from the Sun
[Over the next week or two, I’ll be posting some of the many, many cool astronomical images I’ve been collecting and which are cluttering my computer’s desktop. These are all really cool pictures, and I’m glad I’m finally getting around to writing about them!]
One of my favorite types of objects are things that look like other things. So how can I resist writing about the Pac-Man Nebula, aka NGC 281? As for why it’s called that, duh. The image inset here (click to powerpelletenate) was taken using a telescope that sees optical light, the kind our eyes see.
The resemblance is obvious, isn’t it? If you’re my age or younger, than Pac-Man is pretty much all you can see there (and it’s not the only cosmic object to look like that, either). Of course, as an astronomer, I also see hydrogen (red), oxygen (yellowish-green), dust (black; it absorbs optical light), and evidence of star formation. Those finger-like things on the left are formed when young stars blast out fierce amounts of ultraviolet light, and eat away at the gas surrounding them. Think of them like sandbars eroding under a current. Still, all-in-all: this is clearly Pac-Man, albeit one over 9000 light years away.
But what happens when you look with telescopes that see other kinds of light? Like, say, infrared and X-ray? Then things look really different. Opposite, even!
What do I mean by that? Well, let me show you:
See! On the left is a combination of infrared and X-ray observations taken with Spitzer and Chandra, and I scaled the images to show the same field of view. Stuff that’s dark in the optical picture on the right glows brightly in infrared on the left — mostly warm dust. And the pink glow is due to X-rays from the very young, massive, and hot stars in the center of the Pac-Man’s mouth (ghosts?).
Looking at nebulae like this at different wavelengths tells us different stories about them. We learn more about how stars form, and what happens to the nebula itself as they do. Eventually, the stars in the center will explode, becoming supernovae, and will tear the nebula apart. And you know what happens to the nebula then, right?
Image Credits: X-ray: NASA/CXC/CfA/S.Wolk; IR: NASA/JPL/CfA/S.Wolk; Optical: NSF/AURA/WIYN/Univ. of Alaska/T.A.Rector
450 million light years away are two interacting galaxies. Both spirals, they are caught in each other’s gravitational claws. Already distorted and bound, eventually, to merge into one larger galaxy in a few million years, the view we have of them from Earth is both amazing and lovely… and hey: they’re punctuating their own predicament!
[Click to exclamatenate.]
Looking a lot like an exclamation point, the two galaxies together are called Arp 302 (or VV 340). This image is a combination of pictures from the Chandra X-Ray Observatory (purple) and Hubble (red, green, and blue). The bottom galaxy is a face-on spiral, while the upper one is seen more edge-on, giving the pair their typographical appearance.
I love clever art, especially when that art has a deeper meaning… literally and figuratively.
Check out Japanese artist Takayuki Hori’s X-ray animal origami:
Pictures of the animal bones are printed on transparent paper, so when assembled you get a complete skeleton. They’re beautiful and a bit eerie… and the message the artist is conveying is about pollution in Japan that is threatening and killing wildlife there.
Tip o’ the lead apron to Geekologie.
Hot (and cold) on the heels of my posting the infrared view of the nearby spiral M33, the European Space Agency just published this incredible picture of our other spiral neighbor, M31, the Andromeda Galaxy!
[Click to galactinate.]
Oh my. This is a composite of two orbiting observatory images: the far infrared using Herschel (colored orange), and the X-ray emission using XMM-Newton (blue). There’s so much to see! That’s not surprising, since at 2.5 million light years away, Andromeda is the closest big galaxy to us, and presents itself with loads of detail.
First, shown here is Robert Gendler’s magnificent visible-light image of the galaxy. You can see it’s tilted almost edge-on to us, but you can see the central bulge of old stars, the spiral arms winding out, the dark lanes of dust. This image has roughly the same orientation and border as the big one above, so you can compare them.
The infrared observations trace the presence of cold dust, created when stars are born and when they die. And by cold, I mean cold: much of it is just a few degrees above absolute zero. That dust is opaque in visible light, as you can see in Gendler’s shot. But it glows in infrared! The X-rays, on the other hand, are from incredibly hot gas heated to millions of degrees by neutron stars, black holes, and newly-born massive stars; you can see several individual objects in the galaxy’s core. Read More
In June, I posted about a pinup calendar where the model was somewhat more naked than naked: in fact, the pictures were all X-rays!
I was fascinated by the implied raciness of the pictures, given that at best all you could see was a hint of curves. The poses themselves were provocative as well, and I wanted to spark a discussion of it.
One thing that should have occurred to me but didn’t was how the pictures themselves were made. Was a model exposed to X-rays? How much were the images enhanced? Were they real at all?
What’s more naked than naked?
That picture is one of a dozen making up an unusual — to say the least! — pinup calendar. It was put together for EIZO, a monitor manufacturer; their equipment is used to display high-resolution medical displays… like radiographs. So it’s clever, and apropos.
I had to laugh when I saw them. I’m more of a WWII-style pinup kinda guy, but these are really funny. But as I looked at them more, I started to think more deeply about them.