Hubble is the gift that keeps on giving. Check this jaw-dropping stunner:

Holy wow! Click to embiggen, or go here to get a ginormous image.

This is an image of NGC 3603, a vast cloud of gas and dust that is cranking out stars like no one’s business. It’s one of the busiest stellar nurseries in our entire galaxy. That cluster of stars in the center has thousands of newly-born stars in it, including one named NGC 3603A. This bruiser is the most massive star ever to have its mass directly measured: it is a whopping 116 times heftier than the Sun. That’s about as massive as a star can get without tearing itself apart!
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NASA’s fledgling Wide-field Infrared Survey Explorer (WISE) opened its eyes a few weeks ago, and astronomers have just released the first of a torrent of spectacular images from it.

Since its launch last December, WISE has been surveying the sky, taking data continuously as it spins on its axis and orbits the Earth. A few images have been released before, but these new ones are fully processed, scientifically-calibrated, and gorgeous.

I have to start with this one, because it’s just so pretty! Behold Comet C/2007 Q3, aka Siding Spring:

Holy dirty snowballs! That’s gorgeous, a classic comet. When this image was taken, on January 10, 2010, the comet was 340 million kilometers (200 million miles) from Earth. That’s a good ways off, so I’m impressed with the detail of this image! It’s actually a four-color image: blue is 3.6 microns (about 5 times the reddest wavelength the human eye can see, so well out into the infrared), green is 4.6, orange is 12, and red is 22 microns.

Since the temperature of an objects determines the kind of light it emits, we can estimate the temperature of the comet just by eyeballing this picture. It’s mostly orange, meaning the comet is pouring out light at 12 microns. A human being radiates infrared from about 7 to 14 microns, so this means the parts of the comet emitting IR (and therefore seen by WISE in this image) are around the same temperature as a person! Well, in physics terms; in human terms it’s pretty cold, about -40 Celsius. And it’ll get even colder now since it’s on its way out of the inner solar system, away from the Sun’s warmth. It’ll dim as it cools, too, returning back to invisibility once again.

WISE is expected to see quite a few comets, and in fact discovered its first just a few days ago. I wonder how many it’ll find, and if they’ll all be this pretty…?

Let’s take a step farther out for the next WISE image:

Recognize that galaxy? I wouldn’t blame you if you didn’t, but it’s Andromeda! That’s the nearest large spiral to our Milky Way. It’s roughly 2.9 million light years away (estimates vary) and can be seen by the naked eye from a dark site. This stunning photo really accentuates how amazing WISE is: the field of view is 5 degrees across, the width of ten full Moons. The Hubble camera I used to work with would barely cover a pixel in this image!

Remember, this image is all infrared. What looks blue here is actually cold stuff compared to what we’re used to: old red stars, for example. The colors are a little different than in the comet image, but red is still the coolest material: dust. These complex molecules are created when massive stars are born and when they die. Since massive stars don’t live long, they tend to die near where they were born, so you see the dust constrained to very narrow areas where star formation occurs. Less hefty stars (like the Sun) live long enough to drift away from their nursery over billions of years, so they fill the galaxy’s disk (in blue). That’s why the dust is so vivid and tightly defined in this image.

If you look closely, you can see the left side of the galaxy is a bit distorted. That’s called a warp, and is probably caused by a nearby pass of another galaxy, or one Andromeda actually absorbed. The fuzzy blob just below the main galaxy is a dwarf elliptical companion to Andromeda, orbiting it like the Moon orbits the Earth. It’s mostly composed of old stars that look red to our eye, so again it’s blue in this false color image.

OK, one more. I like this one a lot: NGC 3603, a star-forming region about 20,000 light years from Earth:

It may not look familiar, but if you’ve been reading my blog for more than a couple of weeks, you’ve seen it: I wrote about a Hubble image of this very nebula. Now, if you’re like me, you’ll click that link, look at the Hubble image, and then try to figure out where it fits in this WISE shot. Pbbbt. Don’t bother. The Hubble image is only a tiny portion of this vast vista, a blip right in the middle of the brightest part of the WISE image. The S in WISE is for "Survey", which means it takes pictures of ginormous swaths of sky, far more than Hubble can do. In fact, Hubble could take picture after picture for weeks and not get a view of the sky as large as WISE does in a few minutes (of course, the Hubble image would be a whole lot more detailed…).

In this image, as before, red is warm dust, and blue is hotter material like stars. The green is what gets me though: at 12 microns, that reveals PAHs, polycyclic aromatic hydrocarbons. These complex organic compounds form in cool conditions in nebulae, which are lousy with them. They’re everywhere where the temperature isn’t too high to disintegrate them. They can form even larger molecules, and some people think they may be important in creating the molecules necessary for life on Earth. That’s not to say those molecules form in nebulae like NGC 3603 and then somehow get here; they most likely form right here as well. The point is, they look like they’re pretty easy to make if conditions are right… on Earth as it is in the heavens.

And the sheer size and breadth of the nebula is simply stunning! I’m so used to narrow fields of view that I forget sometimes just how large these objects are. This nebula is dozens of light years across, forming thousands upon thousands of stars. It’s among the biggest such star factories in our galaxy, and is certainly easily visible from other galaxies as well. Even from 20,000 light years away — 1/5 of the way across our entire galaxy — it’s clearly a formidable object.

And that’s the strength of WISE. It can see large objects, investigate the bigger picture of the sky, and do it in the longest regions of the infrared spectrum, light that we simply cannot explore from the ground — our air absorbs it, and all the warm objects around us glow fiercely at those energies. It would be like trying to find a firefly against the Sun! So we must launch observatories into space to peer at the far infrared light from cosmic objects, and WISE will be our eyes to do just that.

And from these images it looks like it’ll do a fine job. I’m impressed with these images. I’ve seen a few early release observations in my time — I’ve made a few myself! — and these are excellent. The whole mission is only supposed to last a few months; there is coolant on board for the detectors that can only go so far. In that short time it has a whole sky to observe, and that’s a lot of space. But that also means there’s a lot to see: galaxies, asteroids, comets, nebulae… maybe even a gamma-ray burst or two. The next few months will be very exciting for infrared astronomy!

Related posts:
WISE uncovers its first near-Earth asteroid
First light for WISE
The terrible beauty of chaotic starbirth
Spitzer peeks under a cradle’s blanket

Images credit: NASA/JPL-Caltech/UCLA

What’s better than a gorgeously stunning image of a massive cluster surrounded by delicate, wispy nebulosity?

Well, nothing, really. Unless you can use it for SCIENCE!

[Click to gigantisize.]

Purty, ain’t it? That’s NGC 3603, a very large star-forming region in our own Milky Way Galaxy, lying about 20,000 light years away. It can only be seen from the southern hemisphere, which is why the European Southern Observatory folks got this image using the ginormous Very Large Telescope, an 8-meter behemoth in Chile (and actually, Ginormous Telescope would be a cool name).

Not too long ago — no more than a million years, give or take — a lot of the stars forming the central cluster there were born. There are so many that they appear to overlap, but that’s an illusion due to the blurring of the image from the Earth’s atmosphere (and the nature of light itself only allows us to make star images so small).

Lost in that crowd is a star designated NGC 3603 A1, and it is the most massive star to ever have its mass directly measured. It’s actually a binary star, two monsters locked in a gravitational dance, orbiting each other once every 3.77 days — which right away tells you this is a special pair, possessing enough gravity to toss themselves around that rapidly.

Using simple laws of physics discovered by Kepler back in the 1600s, we can measure the masses of each star in the duo. The heftier of the two is a whopping 116 times the mass of the Sun — which is close to the upper limit of what a star can get to without tearing itself apart. The more massive a star, the more luminous it is, and the surface can get so hot that any material there gets blown off… so that sets a lid on how big a star can get. Details vary depending on a lot of factors, but really 116 times the mass of the Sun is about as big as you’ll ever get for a star in our galaxy.

The other star in the binary is no slouch, tipping the scales at 89 solar masses. If it were just sitting out there all by itself it would rate as a phenomenal star, too. But its partner still wins the prize.

And how do I know those stars were born no more than a million years ago? Because massive stars don’t live long, and any beasts like these two live short lives indeed. It won’t be long before they detonate as supernovae, lighting up with a violence and fury that will make each outshine the rest of the stars in our entire galaxy combined!

Not only that, but pretty much every star you see in that cluster is of the massive and luminous classes astronomers call O and B stars, bruisers with enough oomph to explode as supernovae. How many stars do you see in that cluster? Dozens? So think about that: each one of those will become a titanic supernova, wreaking havoc across dozens of light years, sending out blasts of light to outshine galaxies, and throwing out octillions of tons of gas.

Eventually that gas, laced with heavier elements created in the nuclear forge of the supernova blast wave itself, will slam into, merge with, and seed the surrounding gas in the nebula. Compressed beyond its ability to sustain itself, the gas will collapse and form more stars. Some of these may be massive ones which will again repeat the cycle, and some will have lower mass, be fainter, cooler. They may form planets from those heavy elements. It will be a rocky birth, given the environment, but the vagaries of orbital dynamics dictate that eventually those systems will leave the nebula and move out on their own in the Milky Way. And a billion years from now, two, four billion, who knows what creatures may roam the surfaces of any of those worlds.

And will they see more stellar factories dotting the galaxies starscape, and wonder what their own looked like, all those eons ago?