Ho hum, another boring gorgeous sparkling beehive of stars

By Phil Plait | May 10, 2012 6:45 am

Orbiting our galaxy in the lonely depths of intergalactic space, 160+ globular clusters are among the oldest structures we know. They’re composed of thousands, sometimes hundreds of thousands, of stars, all held together by their mutual gravity. I always think of them as beehives, with the stars buzzing around on orbits all tilted willy-nilly.

The European Southern Observatory just released this picture of the globular cluster M55 using the VISTA telescope., and it’s very pretty:

[Click to englobulenate, or grab the 6Mb 3k x 3k pixel version!]

Honestly, there’s not a lot of science I can add to this that I haven’t written about a bazillion times before (see Related Posts, below). M55 is 17,000 light years away toward the galactic center, which is relatively close as these things go. It’s big, 100 light years across, so from Earth it looks to be roughly 2/3 the size of the Moon. In this unusual picture by VISTA, we’re seeing it in infrared — at 1 micron (colored blue in the picture) and 1.5 microns (colored red), so stars that look red are really much cooler than the Sun.

But other than that, it’s just another run-of-the-mill globular. Which is remarkable enough! And you know what: despite their clunky name, there’s no such thing as an ugly globular cluster. That’s reason enough to share this lovely picture.

Image credit: ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit

Related Posts:

Desktop Project Part 12: The galactic deep diver M9
Desktop Project Part 3: The massive massiveness of M54
Gorgeous globular hides hundreds of rejuvenated stars
Lonely sentinel of the galaxy

CATEGORIZED UNDER: Astronomy, Pretty pictures

To grasp a billion stars

By Phil Plait | April 4, 2012 6:00 am

There are times — rare, but they happen — when I have a difficult time describing the enormity of something. Something so big, so overwhelming, that words simply cannot suffice.

The basic story is: Using the VISTA telescope in Chile and the UKIRT telescope in Hawaii, astronomers have made an incredibly detailed map of the sky in infrared. This map will help understand our own galaxy, more distant galaxies, quasars, nebulae, and much more.

But what do I mean by "incredibly detailed"?

This is where words get hard. So hang on tight; let me show you instead.

Here’s a section of the survey they made, showing the star-forming region G305, an enormous cloud of gas about 12,000 light years away which is busily birthing tens of thousands of stars:

[Click to enstellarnate.]

Pretty, isn’t it? There are about 10,000 stars in this image, and you can see the gas and dust that’s forming new stars even as you look.

But it’s the scale of this image that’s so amazing. It’s only a tiny, tiny part of this new survey. How tiny? Well, it came from this image (the area of the first image is outlined in the white square):

Again, click to embiggen — it’ll blow your socks off. But we’re not done! That image is a subsection of this one:

… which itself is a subsection of this image:

Sure, I’ll admit that last one doesn’t look like much, squished down into a width of a few hundred pixels here for the blog. So go ahead, click on it. I dare you. If you do, you’ll get a roughly 20,000 x 2000 pixel picture of the sky, a mosaic made from thousands of individual images… and even that is grossly reduced from the original survey.

How big is the raw data from the survey? Why, it only has 150 billion pixels aiieeee aiieeeeee AIIEEEEE!!!

And this would be where I find myself lacking in adjectives. Titanic? Massive? Ginormous? These all fail utterly when trying to describe a one hundred fifty thousand megapixel picture of the sky.


And again, why worry over words when I can show you? The astronomers involved helpfully made the original data — all 150 billion pixels of it — into a pan-and-zoomable image where you can zoom in, and in, and in. It’s hypnotizing, like watching "Inception", but made of stars.

And made of stars it is: there are over a billion stars in the original image! A billion. With a B. It’s one of the most comprehensive surveys of the sky ever made, and yet it still only scratches the surface. This survey only covers the part of the sky where the Milky Way galaxy itself is thickest — in the bottom image above you can see the edge-on disk of our galaxy plainly stretching across the entire shot — and that’s only a fraction of the entire sky.

Think on this: there are a billion stars in that image alone, but that’s less than 1% of the total number of stars in our galaxy! As deep and broad as this amazing picture is, it’s a tiny slice of our local Universe.

And once again, we’ve reached the point where I’m out of words. Our puny brains, evolved to count the number of our fingers and toes, to grasp only what’s within reach, to picture only what we can immediately see — balk at these images.

But… we took them. Human beings looked up and wondered, looked around and observed, looked out and discovered. In our quest to seek ever more knowledge, we built the tools needed to make these pictures: the telescopes, the detectors, the computers. And all along, the power behind that magnificent work was our squishy pink brains.

A billion stars in one shot, thanks to a fleshy mass of collected neurons weighing a kilogram or so. The Universe is amazing, but so are we.

Images credit: Mike Read (WFAU), UKIDSS/GPS and VVV

Related Posts:

Tour the galaxy with this pan-and-scan all-sky picture!
What does a half million galaxies look like?
An ultradeep image that’s *full* of galaxies!
Adler planetarium unleashes 2.5 gigapixel image of the galaxy
The new VLT Survey Telescope delivers spectacular images

MORE ABOUT: Milky Way, stars, UKIRT, VISTA

An ultradeep image that's *full* of galaxies!

By Phil Plait | March 23, 2012 6:00 am

What happens when you take a monster 4.1 meter telescope in the southern hemisphere and point it at the same patch of sky for 55 hours?

This. Oh my, this:

[Click to embiggen.]

OK, I know. At first glance it doesn’t look like much, does it? Just a field of stars. However, here’s the important bit: I had to take the somewhat larger original image and reduce it in size to fit my 610-pixel-wide blog. So how much bigger is the original?

It’s 17,000 x 11,000 pixels! If you happen to be sitting on a T1 line, then you can grab this massive 250 Mb file. And I surely suggest you do.

Because yeah, the brightest objects you see in this are stars. Probably a few hundred of them. But you have to look at the bigger image ! Why? Because what’s amazing, truly jaw-dropping and incredible is this:

There are over 200,000 galaxies filling this image!

Ye. Gads.

Here’s a zoom of the image, centered on what looked to me to be one of the biggest galaxies in the frame, a nice edge-on spiral.

With the exception of a handful of blue-looking stars, everything in this zoom is a galaxy, probably billions of light years away. Those tiny red dots are galaxies so far away they crush our minds to dust: we’re seeing them with light that left them shortly after the Universe itself formed.

This light is ancient. And it came a long, long way.

By the way, that picture of the spiral there is not even at full resolution! Just to give you an idea, I cropped out just that galaxy in the full-res image and inset it here. If you want to find it in the full frame, it’s about one-third of the way in from the left, and one-third of the way down from the top. Happy hunting.

[Edited to add: I forgot to add that this galaxy is warped! See how the disk flares up on the left and down on the right, just a bit? This is very common in disk galaxies, and our own Milky Way does it too (see #9 at that link). It’s usually caused when a nearby galaxy’s gravity torques on the stars in the disk.]

These images were taken with VISTA, the European Southern Observatory’s Visible and Infrared Survey Telescope for Astronomy (VISTA), a 4.1 meter telescope in Chile. This huge image is actually composed of 6000 separate images, and is the single deepest infrared picture of the sky ever taken with this field of view. Hubble can get deeper, for example, but sees a much, much smaller part of the sky.

Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

The Helix screams in infrared

By Phil Plait | January 19, 2012 6:45 am

About 700 light years away sits the expanding death cry of a star: the Helix Nebula, a four-light-year wide gas cloud blasted out when a star that was once like the Sun gave up its life.

A new image of it in colors just outside what the human eye can see shows just how much it does look like a screaming star:

[Click to ennebulenate, or download the huge 6600 x 600 pixel 35 Mb version.]

This image is in the near-infrared, taken using the European Southern Observatory’s Visible and Infrared Survey Telescope for Astronomy (VISTA), a 4.1 meter telescope in Chile. Equipped with a whopping 67 megapixel camera it can take pictures of large areas of the sky. The Helix nebula fits that bill: it’s close enough to us that it’s nearly the size of the full Moon in the sky.

This image is pretty nifty. It accentuates cooler gas than what we see in visible light. What’s colored red in the picture is actually infrared light coming from molecular hydrogen, and shows the sharp ring-like edge of the nebula. What you’re seeing here is not so much a ring as it is the walls of a barrel-like structure, and we happen to be seeing it nearly right down the tube (see Related posts below for all the info you could want on this amazing object).

It also accentuates the long, long streamers pointing directly away from the center. Those are comet-like tails coming from denser clumps of material boiling away as the fierce ultraviolet light of the central star floods out, their material flowing radially outward. This is seen in other nebulae as well.

And while it’s beautiful and scientifically very useful (I would’ve killed for data this nice when I was researching these nebulae in grad school), it’s also something of an existential reminder: someday, our own Sun will look a bit like this. Probably not quite this bright and well-defined; our local star doesn’t quite have the power needed to light up its surroundings this way. But for all intent and purpose, you’re seeing a snapshot of our solar system in seven or eight billion years.

Just in case you needed a little perspective this morning.

Image credit: ESO/VISTA/J. Emerson. Acknowledgment: Cambridge Astronomical Survey Unit

Related posts:

The Helix’s dusty heart
Top 10 Astronomy Pictures of 2007: Runners Up
Down the throat of a dying star
Thus spoked the Dumbbell

The Milky Way's buried treasures

By Phil Plait | August 3, 2011 10:00 am

When I was younger, I’d haul my ‘scope out to the driveway and peruse the heavens. Some of my favorite targets were open clusters: loose aggregations of stars that had dozens or even hundreds of members. These stars are all in the family, born by the same cloud of gas and still bound together by their own gravity.

A lot of these objects are big and bright, easily visible in binoculars — those tend to be close to us in space — and others fainter, harder to spot. Most of those latter ones are just farther away, but some are partially obscured by galactic dust, which robs them of light, like a curtain in a window partially blocking the light form outside.

I used to wonder how many open clusters the Milky Way sported. Thousands, I figured, and I also guessed a lot had been cataloged. But how many were behind such thick curtains of dust, hidden from our view? Some estimates are that there as many as 30,000 such groups. And now we’re starting to find them.

[Click to embiggen, or grab the ginormous 2400 x 2100 pixel version.]

That gorgeous shot is from the European Southern Observatory’s Visible and Infrared Survey Telescope for Astronomy (VISTA), a 4.1 meter ‘scope sitting in northern Chile that sports a 67 megapixel camera. It’s optimized to view the skies in infrared light, which can travel through dust clouds, revealing what lies behind. This picture shows 9 of the 96 new clusters detected by a survey that started only last year! And I had to crop it to fit the blog; the hi-res shot shows 30 clusters in total.

Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures, Top Post
MORE ABOUT: dust, open clusters, VISTA

Spectacular VISTA of the Tarantula

By Phil Plait | August 11, 2010 10:31 am

Ever wanted to see a Tarantula up close? Up really close? Here’s your chance!

[Click to hugely enarachnidate, or grab the atomically-mutated, 130 Mb, 9000 x 12000 pixel megaspider version here. But be ye fairly warned, says I: you’ll lose your afternoon looking at it.]

That is a new image of the Tarantula Nebula (ha! Got you!) from the European Southern Observatory’s VISTA survey telescope in Chile. The telescope can see in the near-infrared, just outside the range of our human vision, and is being used to map a big chunk of the southern sky.

The Tarantula is a sprawling star-forming region in the Large Magellanic Cloud, a small companion galaxy to our own Milky Way Galaxy. Of course, "small" is a matter of perspective; the LMC is still tens of thousands of light years across and has several billion stars in it. From its distance of 180,000 light years, the LMC appears as a smudge in the sky to the unaided eyes of southern observers.

In astronomy terms the image above is huge; it covers a square degree of sky, several times the area of the full Moon! However, in real terms, if you lived in the southern hemisphere and went outside on a clear night, you could block out the entire region of the picture with the tip of one finger held at arm’s length.
Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Sculpting a barred galaxy

By Phil Plait | June 17, 2010 7:19 am

I love big, splashy spiral galaxies. They are such eye candy, and of course their breadth and scale are magnificent. Sweeping, curved arms of stars and gas a hundred thousand light years long…

One of my favorites is NGC 253, a nearly edge-on spiral that lies roughly 11 million light years away in the constellation of Sculptor. I’ve seen it many, many times, but I was honestly surprised when a new image was released by the European Southern Observatory. I’ve never seen it like this:


Wow! Click to galactinate.

As you can see, it’s tilted pretty severely to our line of sight. You can clearly see the spiral arms, and the dust lanes wrapping around the galactic center. I was amazed to see the dust appears to be thicker on the top half than on the bottom. I was even more amazed to clearly see the bar — the elongated rectangular region in the center of the galaxy! That’s almost completely undetectable in a visible light image of the galaxy:
Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Incredible VISTA of the cosmos

By Phil Plait | December 11, 2009 8:07 am

Astronomers with the European Southern Observatory have just revealed the first images from their new telescope called VISTA: the Visible and Infrared Survey Telescope for Astronomy. If ever there was an appropriate name for a ‘scope, that’s it.


Here’s why:


Oh baby. Yeah, click it to embiggen.

This image is of the Flame Nebula, a star forming gas cloud in Orion. The image itself covers about half a square degree on the sky (twice the area of the full Moon) and shows details of the nebula, including the core made up of stars invisible to optical telescopes. The bright star in the image is the monster blue supergiant Alnitak, which is the easternmost (left, to northern observers) star in Orion’s belt. Get a good look at it, because in a million years or so that star is gonna blow.

Can you spot the famous Horsehead Nebula in this picture? It looks a little different than you usually see it, because VISTA operates in the visible and near-infrared. It uses a 4.1 meter mirror (that’s big, folks) to suck down light from the sky. It is extremely sensitive and produces very high-resolution images… as you’d expect from a ‘scope that has a 67 million pixel detector.

That’s so many pixels you’d think they’d make an image you could zoom into. Oh wait: they did. You’ll have some fun playing with that; in fact, if you spend more than 14 minutes playing with it you’ll have spent longer than it took to take this image! That’s right, that gorgeous shot is only a 14 minute exposure.

vista_starfieldHere’s another phenomenal picture. It’s an amazing 2 x 1.5 degree field toward the center of the Milky Way, revealing about a million stars! It’s taken completely in the near infrared, just outside of what the human eye can see, and shows dust and stars mostly invisible in optical light. As you can see, the center of our Galaxy is a mess. Getting images in different wavelengths of light allows us to get a better handle on what’s happening in this incredibly crowded volume of space.

And yeah, this image is zoomable too. You absolutely want to take that little tour; I literally gasped when I saw it.

vista_fornaxThere’s also this very pretty shot of the Fornax galaxy cluster, a collection of galaxies 60 million light years away. This 25 minute exposure captures quite a few galaxies. Like before, it’s shots like this that help scientists get a handle on not just individual objects, but the environment in which they live, too. If you want to see that environment for yourself, why, tour the zoomable image.

vista_detectorFinally, let me leave you with this remarkable photo, showing the VISTA camera itself. Note the dude standing on the left. VISTA is huge! It weighs three tons, and I suspect most of that is the support equipment for it, including a dewar that holds the liquid nitrogen needed to cool the detector down to -200° C. See the glass in the front? That’s the largest IR-transparent window ever created.

It’s hard to believe that such a hulking camera can take such fine, detailed images, but that’s how these things work. A lot of times in astronomy, bigger is better… especially when it allows us to take such deep images of the cosmos.

Credits: Credit: ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit; ESO/Y. Beletsky.

CATEGORIZED UNDER: Astronomy, Pretty pictures

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