[The Desktop Project is my way of a) forcing me to write something every day by 2) posting a brief article about all the astronomical images I've collected on my computer's desktop. I'm actually getting ahead of the onslaught, so I'm thinking this week may see me catching up!]
M82 is classified as an irregular galaxy — that is, one that has no overall shape, but instead a weird, splotchy configuration. When you see a picture of it, you’ll see why… and Adam Block of the Mt. Lemmon SkyCenter has a great one!
See what I mean? You can see an underlying galaxy there, but all that red stuff certainly makes it look, well, irregular.
… but wait a sec. If you look at just the galaxy (the blue stuff), it bears more than a striking resemblance to a run-of-the-mill — if heavily warped — edge-on spiral galaxy. And all that red stuff appears to be emanating from the center, as if its being blown from the core of the galaxy like a giant wind!
This, it so happens, is exactly what’s going on. And the reason is that M82 is prolifically fecund: it’s undergoing an intense burst of star formation, creating stars at a rate far exceeding that of the Milky Way.
Young stars can be extremely energetic, blowing out tremendous winds of gas. All that red stuff is actually warm hydrogen, blasting away from the center of the galaxy where all that star birth is occurring. In fact, there may be as many as 200 clusters of stars in the core of M82, in total containing tens of millions of stars. That’s a lot of engines to drive out that gas. No wonder astronomers used to think the core of the galaxy was exploding! But now we know it’s the opposite: it’s not the deaths of thousands of stars creating that chaos, it’s the births of millions of them.
So what caused this incredible profusion of new stars? M82 lies close to a bigger spiral galaxy called M81, and there’s some indication they are gravitationally interacting. A near collision between the two some time ago may have stirred up the gas in M82, causing it to drop to the center of the galaxy where it became the raw material to build stars.
You might think a collision between two galaxies would result in nothing but calamity. But again, the opposite is true! In astronomy — in everything, really — you have to be careful about your presuppositions. The Universe doesn’t care very much what you think, and will continue to behave according to the laws of nature. We’re the ones who have to change and adapt to what it’s telling us.
Image credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona
- M82 stifles a cosmic belch
- Attack of the galactic subatomic particles
- Not all halos are created equal
- In galactic collisions, might makes right
- M81, up close and personal
- Happy birthday, HST!
- Sometimes a cigar galaxy is just a cigar galaxy
So you saw my gallery yesterday of gorgeous pictures from 2011, right? And then you read my post this morning where I whine about how Chandra releases an awesomely cool picture the day after I put up my gallery?
Right. So of course Hubble releases an image today that is so insanely amazing I hardly know where to start with it.
So I’ll start by showing it to you. Behold, Sharpless 2-106:
Are. You. Freaking. Kidding. Me? [Click to ennbulenate, and yes, you really want to.]
This devastatingly beautiful image shows the birth pangs of a massive star. Called IRS 4 (for Infrared Source 4; it was first seen in IR images), it’s the really bright star just below center where the two blue lobes come together. It’s a bruiser, an O-type star with at least 15 times the Sun’s mass — 30 octillion tons! — and is a staggering 10,000 times as bright. It’s still in the process of forming, but it’s nearly there.
Located about 2000 light years away, IRS 4 is surrounded by an enormous cloud of gas and dust that may have a mass as high as 25,000 times the mass of the Sun. When the star first ignited, fusing hydrogen into helium in its core, the vast amount of energy it started pouring out lit up the cloud in the immediate vicinity around it. Most of the cloud is still dark and cannot be seen here, but everything within a few light years of the star is being illuminated, if not ionized, by the fierce ultraviolet light from the star.
Generally, very young stars are still surrounded by the thick disk of material from which they formed. That’s true of IRS 4; the dark line on the left of the star is actually the shadow of that disk on the gas and dust around it.
At this point, things get weird.
I know I’ve been posting a lot of astropr0n lately, but there’s just been so much cool stuff the past few days (and there’s more to come)! The European Space Agency just threw their hat into the ring with this crazy cool image of a young star blowing its stack:
[Click it to ennebulanate, or grab yourself some megasized 2100 x 2100 pixel action.]
I love this image! It shows the havoc caused by young stars as they spew out material at speed upwards of a million kilometers per hour. What you’re seeing is actually a small part of a star-forming region surrounding the star R Corona Australis, a nearby 550 light years away. It’s a densely packed cloud of thick dust and gas, completely hiding the stars inside and behind it. It’s not terribly big, only a couple of light years across — compare that to the Orion Nebula, which is 20 light years across (and that’s only the visible portion; it’s part of a dark cloud that’s much larger). Or the Tarantula nebula, which I posted about yesterday, which is a thousand light years across!
Even though it’s small, it’s the birthplace of many stars. Two such stars reveal their presence here; not by their light, but by blowing out long streamers of matter called jets. Read More
For centuries, scientists have wondered how stars were born. There were lots of ideas, but precious little evidence to back them up.
That’s changed recently. Oh baby, how that’s changed. Check out this gorgeous image of the star-forming compact gas cloud called GL490:
You have to click that to get the ginormous 6000 x 6000 pixel version! It’s stunning.
This image is a combination of pictures taken by the Spitzer Space Telescope and the 2 Micron All-Sky Survey, or 2MASS. Both telescopes scan the sky in the infrared, well outside what our eyes can see. In this false-color image, blue represents 2.2 microns (the reddest light our human eyes can detect is about 0.7 microns, so this is three times that wavelength), green is 3.6 microns, and red is 4.5 microns. At these long wavelengths, what you tend to see are objects that astronomers call "warm", but that’s compared to empty space. In non-geek terms, these objects are colder than 100 Kelvin: about -170°C, or -280°F!
The green glow is from PAHs, or polycyclic aromatic hydrocarbons. Again, in non-geek lingo: big molecules of stinky soot. Read More